ecpair.js

(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.ecpair = f()}})(function(){var define,module,exports;return (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
module.exports = require('ecpair');

},{"ecpair":5}],2:[function(require,module,exports){
var Buffer = require('safe-buffer').Buffer
var Transform = require('stream').Transform
var StringDecoder = require('string_decoder').StringDecoder
var inherits = require('inherits')

function CipherBase (hashMode) {
  Transform.call(this)
  this.hashMode = typeof hashMode === 'string'
  if (this.hashMode) {
    this[hashMode] = this._finalOrDigest
  } else {
    this.final = this._finalOrDigest
  }
  if (this._final) {
    this.__final = this._final
    this._final = null
  }
  this._decoder = null
  this._encoding = null
}
inherits(CipherBase, Transform)

CipherBase.prototype.update = function (data, inputEnc, outputEnc) {
  if (typeof data === 'string') {
    data = Buffer.from(data, inputEnc)
  }

  var outData = this._update(data)
  if (this.hashMode) return this

  if (outputEnc) {
    outData = this._toString(outData, outputEnc)
  }

  return outData
}

CipherBase.prototype.setAutoPadding = function () {}
CipherBase.prototype.getAuthTag = function () {
  throw new Error('trying to get auth tag in unsupported state')
}

CipherBase.prototype.setAuthTag = function () {
  throw new Error('trying to set auth tag in unsupported state')
}

CipherBase.prototype.setAAD = function () {
  throw new Error('trying to set aad in unsupported state')
}

CipherBase.prototype._transform = function (data, _, next) {
  var err
  try {
    if (this.hashMode) {
      this._update(data)
    } else {
      this.push(this._update(data))
    }
  } catch (e) {
    err = e
  } finally {
    next(err)
  }
}
CipherBase.prototype._flush = function (done) {
  var err
  try {
    this.push(this.__final())
  } catch (e) {
    err = e
  }

  done(err)
}
CipherBase.prototype._finalOrDigest = function (outputEnc) {
  var outData = this.__final() || Buffer.alloc(0)
  if (outputEnc) {
    outData = this._toString(outData, outputEnc, true)
  }
  return outData
}

CipherBase.prototype._toString = function (value, enc, fin) {
  if (!this._decoder) {
    this._decoder = new StringDecoder(enc)
    this._encoding = enc
  }

  if (this._encoding !== enc) throw new Error('can\'t switch encodings')

  var out = this._decoder.write(value)
  if (fin) {
    out += this._decoder.end()
  }

  return out
}

module.exports = CipherBase

},{"inherits":10,"safe-buffer":29,"stream":58,"string_decoder":73}],3:[function(require,module,exports){
'use strict'
var inherits = require('inherits')
var MD5 = require('md5.js')
var RIPEMD160 = require('ripemd160')
var sha = require('sha.js')
var Base = require('cipher-base')

function Hash (hash) {
  Base.call(this, 'digest')

  this._hash = hash
}

inherits(Hash, Base)

Hash.prototype._update = function (data) {
  this._hash.update(data)
}

Hash.prototype._final = function () {
  return this._hash.digest()
}

module.exports = function createHash (alg) {
  alg = alg.toLowerCase()
  if (alg === 'md5') return new MD5()
  if (alg === 'rmd160' || alg === 'ripemd160') return new RIPEMD160()

  return new Hash(sha(alg))
}

},{"cipher-base":2,"inherits":10,"md5.js":11,"ripemd160":28,"sha.js":31}],4:[function(require,module,exports){
(function (Buffer){(function (){
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
exports.ECPairFactory = exports.networks = void 0;
const networks = require('./networks');
exports.networks = networks;
const types = require('./types');
const randomBytes = require('randombytes');
const wif = require('wif');
const testecc_1 = require('./testecc');
const isOptions = types.typeforce.maybe(
  types.typeforce.compile({
    compressed: types.maybe(types.Boolean),
    network: types.maybe(types.Network),
  }),
);
const toXOnly = (pubKey) =>
  pubKey.length === 32 ? pubKey : pubKey.slice(1, 33);
function ECPairFactory(ecc) {
  (0, testecc_1.testEcc)(ecc);
  function isPoint(maybePoint) {
    return ecc.isPoint(maybePoint);
  }
  function fromPrivateKey(buffer, options) {
    types.typeforce(types.Buffer256bit, buffer);
    if (!ecc.isPrivate(buffer))
      throw new TypeError('Private key not in range [1, n)');
    types.typeforce(isOptions, options);
    return new ECPair(buffer, undefined, options);
  }
  function fromPublicKey(buffer, options) {
    types.typeforce(ecc.isPoint, buffer);
    types.typeforce(isOptions, options);
    return new ECPair(undefined, buffer, options);
  }
  function fromWIF(wifString, network) {
    const decoded = wif.decode(wifString);
    const version = decoded.version;
    // list of networks?
    if (types.Array(network)) {
      network = network
        .filter((x) => {
          return version === x.wif;
        })
        .pop();
      if (!network) throw new Error('Unknown network version');
      // otherwise, assume a network object (or default to bitcoin)
    } else {
      network = network || networks.bitcoin;
      if (version !== network.wif) throw new Error('Invalid network version');
    }
    return fromPrivateKey(decoded.privateKey, {
      compressed: decoded.compressed,
      network: network,
    });
  }
  function makeRandom(options) {
    types.typeforce(isOptions, options);
    if (options === undefined) options = {};
    const rng = options.rng || randomBytes;
    let d;
    do {
      d = rng(32);
      types.typeforce(types.Buffer256bit, d);
    } while (!ecc.isPrivate(d));
    return fromPrivateKey(d, options);
  }
  class ECPair {
    __D;
    __Q;
    compressed;
    network;
    lowR;
    constructor(__D, __Q, options) {
      this.__D = __D;
      this.__Q = __Q;
      this.lowR = false;
      if (options === undefined) options = {};
      this.compressed =
        options.compressed === undefined ? true : options.compressed;
      this.network = options.network || networks.bitcoin;
      if (__Q !== undefined)
        this.__Q = Buffer.from(ecc.pointCompress(__Q, this.compressed));
    }
    get privateKey() {
      return this.__D;
    }
    get publicKey() {
      if (!this.__Q) {
        // It is not possible for both `__Q` and `__D` to be `undefined` at the same time.
        // The factory methods guard for this.
        const p = ecc.pointFromScalar(this.__D, this.compressed);
        // It is not possible for `p` to be null.
        // `fromPrivateKey()` checks that `__D` is a valid scalar.
        this.__Q = Buffer.from(p);
      }
      return this.__Q;
    }
    toWIF() {
      if (!this.__D) throw new Error('Missing private key');
      return wif.encode(this.network.wif, this.__D, this.compressed);
    }
    tweak(t) {
      if (this.privateKey) return this.tweakFromPrivateKey(t);
      return this.tweakFromPublicKey(t);
    }
    sign(hash, lowR) {
      if (!this.__D) throw new Error('Missing private key');
      if (lowR === undefined) lowR = this.lowR;
      if (lowR === false) {
        return Buffer.from(ecc.sign(hash, this.__D));
      } else {
        let sig = ecc.sign(hash, this.__D);
        const extraData = Buffer.alloc(32, 0);
        let counter = 0;
        // if first try is lowR, skip the loop
        // for second try and on, add extra entropy counting up
        while (sig[0] > 0x7f) {
          counter++;
          extraData.writeUIntLE(counter, 0, 6);
          sig = ecc.sign(hash, this.__D, extraData);
        }
        return Buffer.from(sig);
      }
    }
    signSchnorr(hash) {
      if (!this.privateKey) throw new Error('Missing private key');
      if (!ecc.signSchnorr)
        throw new Error('signSchnorr not supported by ecc library');
      return Buffer.from(ecc.signSchnorr(hash, this.privateKey));
    }
    verify(hash, signature) {
      return ecc.verify(hash, this.publicKey, signature);
    }
    verifySchnorr(hash, signature) {
      if (!ecc.verifySchnorr)
        throw new Error('verifySchnorr not supported by ecc library');
      return ecc.verifySchnorr(hash, this.publicKey.subarray(1, 33), signature);
    }
    tweakFromPublicKey(t) {
      const xOnlyPubKey = toXOnly(this.publicKey);
      const tweakedPublicKey = ecc.xOnlyPointAddTweak(xOnlyPubKey, t);
      if (!tweakedPublicKey || tweakedPublicKey.xOnlyPubkey === null)
        throw new Error('Cannot tweak public key!');
      const parityByte = Buffer.from([
        tweakedPublicKey.parity === 0 ? 0x02 : 0x03,
      ]);
      return fromPublicKey(
        Buffer.concat([parityByte, tweakedPublicKey.xOnlyPubkey]),
        { network: this.network, compressed: this.compressed },
      );
    }
    tweakFromPrivateKey(t) {
      const hasOddY =
        this.publicKey[0] === 3 ||
        (this.publicKey[0] === 4 && (this.publicKey[64] & 1) === 1);
      const privateKey = hasOddY
        ? ecc.privateNegate(this.privateKey)
        : this.privateKey;
      const tweakedPrivateKey = ecc.privateAdd(privateKey, t);
      if (!tweakedPrivateKey) throw new Error('Invalid tweaked private key!');
      return fromPrivateKey(Buffer.from(tweakedPrivateKey), {
        network: this.network,
        compressed: this.compressed,
      });
    }
  }
  return {
    isPoint,
    fromPrivateKey,
    fromPublicKey,
    fromWIF,
    makeRandom,
  };
}
exports.ECPairFactory = ECPairFactory;

}).call(this)}).call(this,require("buffer").Buffer)
},{"./networks":6,"./testecc":7,"./types":8,"buffer":51,"randombytes":12,"wif":44}],5:[function(require,module,exports){
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
exports.networks = exports.ECPairFactory = exports.default = void 0;
var ecpair_1 = require('./ecpair');
Object.defineProperty(exports, 'default', {
  enumerable: true,
  get: function () {
    return ecpair_1.ECPairFactory;
  },
});
Object.defineProperty(exports, 'ECPairFactory', {
  enumerable: true,
  get: function () {
    return ecpair_1.ECPairFactory;
  },
});
Object.defineProperty(exports, 'networks', {
  enumerable: true,
  get: function () {
    return ecpair_1.networks;
  },
});

},{"./ecpair":4}],6:[function(require,module,exports){
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
exports.testnet = exports.bitcoin = void 0;
exports.bitcoin = {
  messagePrefix: '\x18Bitcoin Signed Message:\n',
  bech32: 'bc',
  bip32: {
    public: 0x0488b21e,
    private: 0x0488ade4,
  },
  pubKeyHash: 0x00,
  scriptHash: 0x05,
  wif: 0x80,
};
exports.testnet = {
  messagePrefix: '\x18Bitcoin Signed Message:\n',
  bech32: 'tb',
  bip32: {
    public: 0x043587cf,
    private: 0x04358394,
  },
  pubKeyHash: 0x6f,
  scriptHash: 0xc4,
  wif: 0xef,
};

},{}],7:[function(require,module,exports){
(function (Buffer){(function (){
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
exports.testEcc = void 0;
const h = (hex) => Buffer.from(hex, 'hex');
function testEcc(ecc) {
  assert(
    ecc.isPoint(
      h('0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
    ),
  );
  assert(
    !ecc.isPoint(
      h('030000000000000000000000000000000000000000000000000000000000000005'),
    ),
  );
  assert(
    ecc.isPrivate(
      h('79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
    ),
  );
  // order - 1
  assert(
    ecc.isPrivate(
      h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140'),
    ),
  );
  // 0
  assert(
    !ecc.isPrivate(
      h('0000000000000000000000000000000000000000000000000000000000000000'),
    ),
  );
  // order
  assert(
    !ecc.isPrivate(
      h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141'),
    ),
  );
  // order + 1
  assert(
    !ecc.isPrivate(
      h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364142'),
    ),
  );
  // 1 + 0 == 1
  assert(
    Buffer.from(
      ecc.privateAdd(
        h('0000000000000000000000000000000000000000000000000000000000000001'),
        h('0000000000000000000000000000000000000000000000000000000000000000'),
      ),
    ).equals(
      h('0000000000000000000000000000000000000000000000000000000000000001'),
    ),
  );
  // -3 + 3 == 0
  assert(
    ecc.privateAdd(
      h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd036413e'),
      h('0000000000000000000000000000000000000000000000000000000000000003'),
    ) === null,
  );
  assert(
    Buffer.from(
      ecc.privateAdd(
        h('e211078564db65c3ce7704f08262b1f38f1ef412ad15b5ac2d76657a63b2c500'),
        h('b51fbb69051255d1becbd683de5848242a89c229348dd72896a87ada94ae8665'),
      ),
    ).equals(
      h('9730c2ee69edbb958d42db7460bafa18fef9d955325aec99044c81c8282b0a24'),
    ),
  );
  assert(
    Buffer.from(
      ecc.privateNegate(
        h('0000000000000000000000000000000000000000000000000000000000000001'),
      ),
    ).equals(
      h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140'),
    ),
  );
  assert(
    Buffer.from(
      ecc.privateNegate(
        h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd036413e'),
      ),
    ).equals(
      h('0000000000000000000000000000000000000000000000000000000000000003'),
    ),
  );
  assert(
    Buffer.from(
      ecc.privateNegate(
        h('b1121e4088a66a28f5b6b0f5844943ecd9f610196d7bb83b25214b60452c09af'),
      ),
    ).equals(
      h('4eede1bf775995d70a494f0a7bb6bc11e0b8cccd41cce8009ab1132c8b0a3792'),
    ),
  );
  assert(
    Buffer.from(
      ecc.pointCompress(
        h(
          '0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8',
        ),
        true,
      ),
    ).equals(
      h('0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
    ),
  );
  assert(
    Buffer.from(
      ecc.pointCompress(
        h(
          '0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8',
        ),
        false,
      ),
    ).equals(
      h(
        '0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8',
      ),
    ),
  );
  assert(
    Buffer.from(
      ecc.pointCompress(
        h('0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
        true,
      ),
    ).equals(
      h('0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
    ),
  );
  assert(
    Buffer.from(
      ecc.pointCompress(
        h('0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
        false,
      ),
    ).equals(
      h(
        '0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8',
      ),
    ),
  );
  assert(
    Buffer.from(
      ecc.pointFromScalar(
        h('b1121e4088a66a28f5b6b0f5844943ecd9f610196d7bb83b25214b60452c09af'),
      ),
    ).equals(
      h('02b07ba9dca9523b7ef4bd97703d43d20399eb698e194704791a25ce77a400df99'),
    ),
  );
  assert(
    ecc.xOnlyPointAddTweak(
      h('79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
      h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140'),
    ) === null,
  );
  let xOnlyRes = ecc.xOnlyPointAddTweak(
    h('1617d38ed8d8657da4d4761e8057bc396ea9e4b9d29776d4be096016dbd2509b'),
    h('a8397a935f0dfceba6ba9618f6451ef4d80637abf4e6af2669fbc9de6a8fd2ac'),
  );
  assert(
    Buffer.from(xOnlyRes.xOnlyPubkey).equals(
      h('e478f99dab91052ab39a33ea35fd5e6e4933f4d28023cd597c9a1f6760346adf'),
    ) && xOnlyRes.parity === 1,
  );
  xOnlyRes = ecc.xOnlyPointAddTweak(
    h('2c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991'),
    h('823c3cd2142744b075a87eade7e1b8678ba308d566226a0056ca2b7a76f86b47'),
  );
  assert(
    Buffer.from(xOnlyRes.xOnlyPubkey).equals(
      h('9534f8dc8c6deda2dc007655981c78b49c5d96c778fbf363462a11ec9dfd948c'),
    ) && xOnlyRes.parity === 0,
  );
  assert(
    Buffer.from(
      ecc.sign(
        h('5e9f0a0d593efdcf78ac923bc3313e4e7d408d574354ee2b3288c0da9fbba6ed'),
        h('fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140'),
      ),
    ).equals(
      h(
        '54c4a33c6423d689378f160a7ff8b61330444abb58fb470f96ea16d99d4a2fed07082304410efa6b2943111b6a4e0aaa7b7db55a07e9861d1fb3cb1f421044a5',
      ),
    ),
  );
  assert(
    ecc.verify(
      h('5e9f0a0d593efdcf78ac923bc3313e4e7d408d574354ee2b3288c0da9fbba6ed'),
      h('0379be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'),
      h(
        '54c4a33c6423d689378f160a7ff8b61330444abb58fb470f96ea16d99d4a2fed07082304410efa6b2943111b6a4e0aaa7b7db55a07e9861d1fb3cb1f421044a5',
      ),
    ),
  );
  if (ecc.signSchnorr) {
    assert(
      Buffer.from(
        ecc.signSchnorr(
          h('7e2d58d8b3bcdf1abadec7829054f90dda9805aab56c77333024b9d0a508b75c'),
          h('c90fdaa22168c234c4c6628b80dc1cd129024e088a67cc74020bbea63b14e5c9'),
          h('c87aa53824b4d7ae2eb035a2b5bbbccc080e76cdc6d1692c4b0b62d798e6d906'),
        ),
      ).equals(
        h(
          '5831aaeed7b44bb74e5eab94ba9d4294c49bcf2a60728d8b4c200f50dd313c1bab745879a5ad954a72c45a91c3a51d3c7adea98d82f8481e0e1e03674a6f3fb7',
        ),
      ),
    );
  }
  if (ecc.verifySchnorr) {
    assert(
      ecc.verifySchnorr(
        h('7e2d58d8b3bcdf1abadec7829054f90dda9805aab56c77333024b9d0a508b75c'),
        h('dd308afec5777e13121fa72b9cc1b7cc0139715309b086c960e18fd969774eb8'),
        h(
          '5831aaeed7b44bb74e5eab94ba9d4294c49bcf2a60728d8b4c200f50dd313c1bab745879a5ad954a72c45a91c3a51d3c7adea98d82f8481e0e1e03674a6f3fb7',
        ),
      ),
    );
  }
}
exports.testEcc = testEcc;
function assert(bool) {
  if (!bool) throw new Error('ecc library invalid');
}

}).call(this)}).call(this,require("buffer").Buffer)
},{"buffer":51}],8:[function(require,module,exports){
'use strict';
Object.defineProperty(exports, '__esModule', { value: true });
exports.maybe =
  exports.Boolean =
  exports.Array =
  exports.Buffer256bit =
  exports.Network =
  exports.typeforce =
    void 0;
exports.typeforce = require('typeforce');
// exposed, external API
exports.Network = exports.typeforce.compile({
  messagePrefix: exports.typeforce.oneOf(
    exports.typeforce.Buffer,
    exports.typeforce.String,
  ),
  bip32: {
    public: exports.typeforce.UInt32,
    private: exports.typeforce.UInt32,
  },
  pubKeyHash: exports.typeforce.UInt8,
  scriptHash: exports.typeforce.UInt8,
  wif: exports.typeforce.UInt8,
});
exports.Buffer256bit = exports.typeforce.BufferN(32);
exports.Array = exports.typeforce.Array;
exports.Boolean = exports.typeforce.Boolean; // tslint:disable-line variable-name
exports.maybe = exports.typeforce.maybe;

},{"typeforce":41}],9:[function(require,module,exports){
'use strict'
var Buffer = require('safe-buffer').Buffer
var Transform = require('readable-stream').Transform
var inherits = require('inherits')

function throwIfNotStringOrBuffer (val, prefix) {
  if (!Buffer.isBuffer(val) && typeof val !== 'string') {
    throw new TypeError(prefix + ' must be a string or a buffer')
  }
}

function HashBase (blockSize) {
  Transform.call(this)

  this._block = Buffer.allocUnsafe(blockSize)
  this._blockSize = blockSize
  this._blockOffset = 0
  this._length = [0, 0, 0, 0]

  this._finalized = false
}

inherits(HashBase, Transform)

HashBase.prototype._transform = function (chunk, encoding, callback) {
  var error = null
  try {
    this.update(chunk, encoding)
  } catch (err) {
    error = err
  }

  callback(error)
}

HashBase.prototype._flush = function (callback) {
  var error = null
  try {
    this.push(this.digest())
  } catch (err) {
    error = err
  }

  callback(error)
}

HashBase.prototype.update = function (data, encoding) {
  throwIfNotStringOrBuffer(data, 'Data')
  if (this._finalized) throw new Error('Digest already called')
  if (!Buffer.isBuffer(data)) data = Buffer.from(data, encoding)

  // consume data
  var block = this._block
  var offset = 0
  while (this._blockOffset + data.length - offset >= this._blockSize) {
    for (var i = this._blockOffset; i < this._blockSize;) block[i++] = data[offset++]
    this._update()
    this._blockOffset = 0
  }
  while (offset < data.length) block[this._blockOffset++] = data[offset++]

  // update length
  for (var j = 0, carry = data.length * 8; carry > 0; ++j) {
    this._length[j] += carry
    carry = (this._length[j] / 0x0100000000) | 0
    if (carry > 0) this._length[j] -= 0x0100000000 * carry
  }

  return this
}

HashBase.prototype._update = function () {
  throw new Error('_update is not implemented')
}

HashBase.prototype.digest = function (encoding) {
  if (this._finalized) throw new Error('Digest already called')
  this._finalized = true

  var digest = this._digest()
  if (encoding !== undefined) digest = digest.toString(encoding)

  // reset state
  this._block.fill(0)
  this._blockOffset = 0
  for (var i = 0; i < 4; ++i) this._length[i] = 0

  return digest
}

HashBase.prototype._digest = function () {
  throw new Error('_digest is not implemented')
}

module.exports = HashBase

},{"inherits":10,"readable-stream":27,"safe-buffer":29}],10:[function(require,module,exports){
if (typeof Object.create === 'function') {
  // implementation from standard node.js 'util' module
  module.exports = function inherits(ctor, superCtor) {
    if (superCtor) {
      ctor.super_ = superCtor
      ctor.prototype = Object.create(superCtor.prototype, {
        constructor: {
          value: ctor,
          enumerable: false,
          writable: true,
          configurable: true
        }
      })
    }
  };
} else {
  // old school shim for old browsers
  module.exports = function inherits(ctor, superCtor) {
    if (superCtor) {
      ctor.super_ = superCtor
      var TempCtor = function () {}
      TempCtor.prototype = superCtor.prototype
      ctor.prototype = new TempCtor()
      ctor.prototype.constructor = ctor
    }
  }
}

},{}],11:[function(require,module,exports){
'use strict'
var inherits = require('inherits')
var HashBase = require('hash-base')
var Buffer = require('safe-buffer').Buffer

var ARRAY16 = new Array(16)

function MD5 () {
  HashBase.call(this, 64)

  // state
  this._a = 0x67452301
  this._b = 0xefcdab89
  this._c = 0x98badcfe
  this._d = 0x10325476
}

inherits(MD5, HashBase)

MD5.prototype._update = function () {
  var M = ARRAY16
  for (var i = 0; i < 16; ++i) M[i] = this._block.readInt32LE(i * 4)

  var a = this._a
  var b = this._b
  var c = this._c
  var d = this._d

  a = fnF(a, b, c, d, M[0], 0xd76aa478, 7)
  d = fnF(d, a, b, c, M[1], 0xe8c7b756, 12)
  c = fnF(c, d, a, b, M[2], 0x242070db, 17)
  b = fnF(b, c, d, a, M[3], 0xc1bdceee, 22)
  a = fnF(a, b, c, d, M[4], 0xf57c0faf, 7)
  d = fnF(d, a, b, c, M[5], 0x4787c62a, 12)
  c = fnF(c, d, a, b, M[6], 0xa8304613, 17)
  b = fnF(b, c, d, a, M[7], 0xfd469501, 22)
  a = fnF(a, b, c, d, M[8], 0x698098d8, 7)
  d = fnF(d, a, b, c, M[9], 0x8b44f7af, 12)
  c = fnF(c, d, a, b, M[10], 0xffff5bb1, 17)
  b = fnF(b, c, d, a, M[11], 0x895cd7be, 22)
  a = fnF(a, b, c, d, M[12], 0x6b901122, 7)
  d = fnF(d, a, b, c, M[13], 0xfd987193, 12)
  c = fnF(c, d, a, b, M[14], 0xa679438e, 17)
  b = fnF(b, c, d, a, M[15], 0x49b40821, 22)

  a = fnG(a, b, c, d, M[1], 0xf61e2562, 5)
  d = fnG(d, a, b, c, M[6], 0xc040b340, 9)
  c = fnG(c, d, a, b, M[11], 0x265e5a51, 14)
  b = fnG(b, c, d, a, M[0], 0xe9b6c7aa, 20)
  a = fnG(a, b, c, d, M[5], 0xd62f105d, 5)
  d = fnG(d, a, b, c, M[10], 0x02441453, 9)
  c = fnG(c, d, a, b, M[15], 0xd8a1e681, 14)
  b = fnG(b, c, d, a, M[4], 0xe7d3fbc8, 20)
  a = fnG(a, b, c, d, M[9], 0x21e1cde6, 5)
  d = fnG(d, a, b, c, M[14], 0xc33707d6, 9)
  c = fnG(c, d, a, b, M[3], 0xf4d50d87, 14)
  b = fnG(b, c, d, a, M[8], 0x455a14ed, 20)
  a = fnG(a, b, c, d, M[13], 0xa9e3e905, 5)
  d = fnG(d, a, b, c, M[2], 0xfcefa3f8, 9)
  c = fnG(c, d, a, b, M[7], 0x676f02d9, 14)
  b = fnG(b, c, d, a, M[12], 0x8d2a4c8a, 20)

  a = fnH(a, b, c, d, M[5], 0xfffa3942, 4)
  d = fnH(d, a, b, c, M[8], 0x8771f681, 11)
  c = fnH(c, d, a, b, M[11], 0x6d9d6122, 16)
  b = fnH(b, c, d, a, M[14], 0xfde5380c, 23)
  a = fnH(a, b, c, d, M[1], 0xa4beea44, 4)
  d = fnH(d, a, b, c, M[4], 0x4bdecfa9, 11)
  c = fnH(c, d, a, b, M[7], 0xf6bb4b60, 16)
  b = fnH(b, c, d, a, M[10], 0xbebfbc70, 23)
  a = fnH(a, b, c, d, M[13], 0x289b7ec6, 4)
  d = fnH(d, a, b, c, M[0], 0xeaa127fa, 11)
  c = fnH(c, d, a, b, M[3], 0xd4ef3085, 16)
  b = fnH(b, c, d, a, M[6], 0x04881d05, 23)
  a = fnH(a, b, c, d, M[9], 0xd9d4d039, 4)
  d = fnH(d, a, b, c, M[12], 0xe6db99e5, 11)
  c = fnH(c, d, a, b, M[15], 0x1fa27cf8, 16)
  b = fnH(b, c, d, a, M[2], 0xc4ac5665, 23)

  a = fnI(a, b, c, d, M[0], 0xf4292244, 6)
  d = fnI(d, a, b, c, M[7], 0x432aff97, 10)
  c = fnI(c, d, a, b, M[14], 0xab9423a7, 15)
  b = fnI(b, c, d, a, M[5], 0xfc93a039, 21)
  a = fnI(a, b, c, d, M[12], 0x655b59c3, 6)
  d = fnI(d, a, b, c, M[3], 0x8f0ccc92, 10)
  c = fnI(c, d, a, b, M[10], 0xffeff47d, 15)
  b = fnI(b, c, d, a, M[1], 0x85845dd1, 21)
  a = fnI(a, b, c, d, M[8], 0x6fa87e4f, 6)
  d = fnI(d, a, b, c, M[15], 0xfe2ce6e0, 10)
  c = fnI(c, d, a, b, M[6], 0xa3014314, 15)
  b = fnI(b, c, d, a, M[13], 0x4e0811a1, 21)
  a = fnI(a, b, c, d, M[4], 0xf7537e82, 6)
  d = fnI(d, a, b, c, M[11], 0xbd3af235, 10)
  c = fnI(c, d, a, b, M[2], 0x2ad7d2bb, 15)
  b = fnI(b, c, d, a, M[9], 0xeb86d391, 21)

  this._a = (this._a + a) | 0
  this._b = (this._b + b) | 0
  this._c = (this._c + c) | 0
  this._d = (this._d + d) | 0
}

MD5.prototype._digest = function () {
  // create padding and handle blocks
  this._block[this._blockOffset++] = 0x80
  if (this._blockOffset > 56) {
    this._block.fill(0, this._blockOffset, 64)
    this._update()
    this._blockOffset = 0
  }

  this._block.fill(0, this._blockOffset, 56)
  this._block.writeUInt32LE(this._length[0], 56)
  this._block.writeUInt32LE(this._length[1], 60)
  this._update()

  // produce result
  var buffer = Buffer.allocUnsafe(16)
  buffer.writeInt32LE(this._a, 0)
  buffer.writeInt32LE(this._b, 4)
  buffer.writeInt32LE(this._c, 8)
  buffer.writeInt32LE(this._d, 12)
  return buffer
}

function rotl (x, n) {
  return (x << n) | (x >>> (32 - n))
}

function fnF (a, b, c, d, m, k, s) {
  return (rotl((a + ((b & c) | ((~b) & d)) + m + k) | 0, s) + b) | 0
}

function fnG (a, b, c, d, m, k, s) {
  return (rotl((a + ((b & d) | (c & (~d))) + m + k) | 0, s) + b) | 0
}

function fnH (a, b, c, d, m, k, s) {
  return (rotl((a + (b ^ c ^ d) + m + k) | 0, s) + b) | 0
}

function fnI (a, b, c, d, m, k, s) {
  return (rotl((a + ((c ^ (b | (~d)))) + m + k) | 0, s) + b) | 0
}

module.exports = MD5

},{"hash-base":9,"inherits":10,"safe-buffer":29}],12:[function(require,module,exports){
(function (process,global){(function (){
'use strict'

// limit of Crypto.getRandomValues()
// https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues
var MAX_BYTES = 65536

// Node supports requesting up to this number of bytes
// https://github.com/nodejs/node/blob/master/lib/internal/crypto/random.js#L48
var MAX_UINT32 = 4294967295

function oldBrowser () {
  throw new Error('Secure random number generation is not supported by this browser.\nUse Chrome, Firefox or Internet Explorer 11')
}

var Buffer = require('safe-buffer').Buffer
var crypto = global.crypto || global.msCrypto

if (crypto && crypto.getRandomValues) {
  module.exports = randomBytes
} else {
  module.exports = oldBrowser
}

function randomBytes (size, cb) {
  // phantomjs needs to throw
  if (size > MAX_UINT32) throw new RangeError('requested too many random bytes')

  var bytes = Buffer.allocUnsafe(size)

  if (size > 0) {  // getRandomValues fails on IE if size == 0
    if (size > MAX_BYTES) { // this is the max bytes crypto.getRandomValues
      // can do at once see https://developer.mozilla.org/en-US/docs/Web/API/window.crypto.getRandomValues
      for (var generated = 0; generated < size; generated += MAX_BYTES) {
        // buffer.slice automatically checks if the end is past the end of
        // the buffer so we don't have to here
        crypto.getRandomValues(bytes.slice(generated, generated + MAX_BYTES))
      }
    } else {
      crypto.getRandomValues(bytes)
    }
  }

  if (typeof cb === 'function') {
    return process.nextTick(function () {
      cb(null, bytes)
    })
  }

  return bytes
}

}).call(this)}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"_process":56,"safe-buffer":29}],13:[function(require,module,exports){
'use strict';

function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }

var codes = {};

function createErrorType(code, message, Base) {
  if (!Base) {
    Base = Error;
  }

  function getMessage(arg1, arg2, arg3) {
    if (typeof message === 'string') {
      return message;
    } else {
      return message(arg1, arg2, arg3);
    }
  }

  var NodeError =
  /*#__PURE__*/
  function (_Base) {
    _inheritsLoose(NodeError, _Base);

    function NodeError(arg1, arg2, arg3) {
      return _Base.call(this, getMessage(arg1, arg2, arg3)) || this;
    }

    return NodeError;
  }(Base);

  NodeError.prototype.name = Base.name;
  NodeError.prototype.code = code;
  codes[code] = NodeError;
} // https://github.com/nodejs/node/blob/v10.8.0/lib/internal/errors.js


function oneOf(expected, thing) {
  if (Array.isArray(expected)) {
    var len = expected.length;
    expected = expected.map(function (i) {
      return String(i);
    });

    if (len > 2) {
      return "one of ".concat(thing, " ").concat(expected.slice(0, len - 1).join(', '), ", or ") + expected[len - 1];
    } else if (len === 2) {
      return "one of ".concat(thing, " ").concat(expected[0], " or ").concat(expected[1]);
    } else {
      return "of ".concat(thing, " ").concat(expected[0]);
    }
  } else {
    return "of ".concat(thing, " ").concat(String(expected));
  }
} // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith


function startsWith(str, search, pos) {
  return str.substr(!pos || pos < 0 ? 0 : +pos, search.length) === search;
} // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/endsWith


function endsWith(str, search, this_len) {
  if (this_len === undefined || this_len > str.length) {
    this_len = str.length;
  }

  return str.substring(this_len - search.length, this_len) === search;
} // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes


function includes(str, search, start) {
  if (typeof start !== 'number') {
    start = 0;
  }

  if (start + search.length > str.length) {
    return false;
  } else {
    return str.indexOf(search, start) !== -1;
  }
}

createErrorType('ERR_INVALID_OPT_VALUE', function (name, value) {
  return 'The value "' + value + '" is invalid for option "' + name + '"';
}, TypeError);
createErrorType('ERR_INVALID_ARG_TYPE', function (name, expected, actual) {
  // determiner: 'must be' or 'must not be'
  var determiner;

  if (typeof expected === 'string' && startsWith(expected, 'not ')) {
    determiner = 'must not be';
    expected = expected.replace(/^not /, '');
  } else {
    determiner = 'must be';
  }

  var msg;

  if (endsWith(name, ' argument')) {
    // For cases like 'first argument'
    msg = "The ".concat(name, " ").concat(determiner, " ").concat(oneOf(expected, 'type'));
  } else {
    var type = includes(name, '.') ? 'property' : 'argument';
    msg = "The \"".concat(name, "\" ").concat(type, " ").concat(determiner, " ").concat(oneOf(expected, 'type'));
  }

  msg += ". Received type ".concat(typeof actual);
  return msg;
}, TypeError);
createErrorType('ERR_STREAM_PUSH_AFTER_EOF', 'stream.push() after EOF');
createErrorType('ERR_METHOD_NOT_IMPLEMENTED', function (name) {
  return 'The ' + name + ' method is not implemented';
});
createErrorType('ERR_STREAM_PREMATURE_CLOSE', 'Premature close');
createErrorType('ERR_STREAM_DESTROYED', function (name) {
  return 'Cannot call ' + name + ' after a stream was destroyed';
});
createErrorType('ERR_MULTIPLE_CALLBACK', 'Callback called multiple times');
createErrorType('ERR_STREAM_CANNOT_PIPE', 'Cannot pipe, not readable');
createErrorType('ERR_STREAM_WRITE_AFTER_END', 'write after end');
createErrorType('ERR_STREAM_NULL_VALUES', 'May not write null values to stream', TypeError);
createErrorType('ERR_UNKNOWN_ENCODING', function (arg) {
  return 'Unknown encoding: ' + arg;
}, TypeError);
createErrorType('ERR_STREAM_UNSHIFT_AFTER_END_EVENT', 'stream.unshift() after end event');
module.exports.codes = codes;

},{}],14:[function(require,module,exports){
(function (process){(function (){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// a duplex stream is just a stream that is both readable and writable.
// Since JS doesn't have multiple prototypal inheritance, this class
// prototypally inherits from Readable, and then parasitically from
// Writable.

'use strict';

/*<replacement>*/
var objectKeys = Object.keys || function (obj) {
  var keys = [];
  for (var key in obj) keys.push(key);
  return keys;
};
/*</replacement>*/

module.exports = Duplex;
var Readable = require('./_stream_readable');
var Writable = require('./_stream_writable');
require('inherits')(Duplex, Readable);
{
  // Allow the keys array to be GC'ed.
  var keys = objectKeys(Writable.prototype);
  for (var v = 0; v < keys.length; v++) {
    var method = keys[v];
    if (!Duplex.prototype[method]) Duplex.prototype[method] = Writable.prototype[method];
  }
}
function Duplex(options) {
  if (!(this instanceof Duplex)) return new Duplex(options);
  Readable.call(this, options);
  Writable.call(this, options);
  this.allowHalfOpen = true;
  if (options) {
    if (options.readable === false) this.readable = false;
    if (options.writable === false) this.writable = false;
    if (options.allowHalfOpen === false) {
      this.allowHalfOpen = false;
      this.once('end', onend);
    }
  }
}
Object.defineProperty(Duplex.prototype, 'writableHighWaterMark', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState.highWaterMark;
  }
});
Object.defineProperty(Duplex.prototype, 'writableBuffer', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState && this._writableState.getBuffer();
  }
});
Object.defineProperty(Duplex.prototype, 'writableLength', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState.length;
  }
});

// the no-half-open enforcer
function onend() {
  // If the writable side ended, then we're ok.
  if (this._writableState.ended) return;

  // no more data can be written.
  // But allow more writes to happen in this tick.
  process.nextTick(onEndNT, this);
}
function onEndNT(self) {
  self.end();
}
Object.defineProperty(Duplex.prototype, 'destroyed', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    if (this._readableState === undefined || this._writableState === undefined) {
      return false;
    }
    return this._readableState.destroyed && this._writableState.destroyed;
  },
  set: function set(value) {
    // we ignore the value if the stream
    // has not been initialized yet
    if (this._readableState === undefined || this._writableState === undefined) {
      return;
    }

    // backward compatibility, the user is explicitly
    // managing destroyed
    this._readableState.destroyed = value;
    this._writableState.destroyed = value;
  }
});
}).call(this)}).call(this,require('_process'))
},{"./_stream_readable":16,"./_stream_writable":18,"_process":56,"inherits":10}],15:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// a passthrough stream.
// basically just the most minimal sort of Transform stream.
// Every written chunk gets output as-is.

'use strict';

module.exports = PassThrough;
var Transform = require('./_stream_transform');
require('inherits')(PassThrough, Transform);
function PassThrough(options) {
  if (!(this instanceof PassThrough)) return new PassThrough(options);
  Transform.call(this, options);
}
PassThrough.prototype._transform = function (chunk, encoding, cb) {
  cb(null, chunk);
};
},{"./_stream_transform":17,"inherits":10}],16:[function(require,module,exports){
(function (process,global){(function (){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

module.exports = Readable;

/*<replacement>*/
var Duplex;
/*</replacement>*/

Readable.ReadableState = ReadableState;

/*<replacement>*/
var EE = require('events').EventEmitter;
var EElistenerCount = function EElistenerCount(emitter, type) {
  return emitter.listeners(type).length;
};
/*</replacement>*/

/*<replacement>*/
var Stream = require('./internal/streams/stream');
/*</replacement>*/

var Buffer = require('buffer').Buffer;
var OurUint8Array = (typeof global !== 'undefined' ? global : typeof window !== 'undefined' ? window : typeof self !== 'undefined' ? self : {}).Uint8Array || function () {};
function _uint8ArrayToBuffer(chunk) {
  return Buffer.from(chunk);
}
function _isUint8Array(obj) {
  return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
}

/*<replacement>*/
var debugUtil = require('util');
var debug;
if (debugUtil && debugUtil.debuglog) {
  debug = debugUtil.debuglog('stream');
} else {
  debug = function debug() {};
}
/*</replacement>*/

var BufferList = require('./internal/streams/buffer_list');
var destroyImpl = require('./internal/streams/destroy');
var _require = require('./internal/streams/state'),
  getHighWaterMark = _require.getHighWaterMark;
var _require$codes = require('../errors').codes,
  ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
  ERR_STREAM_PUSH_AFTER_EOF = _require$codes.ERR_STREAM_PUSH_AFTER_EOF,
  ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
  ERR_STREAM_UNSHIFT_AFTER_END_EVENT = _require$codes.ERR_STREAM_UNSHIFT_AFTER_END_EVENT;

// Lazy loaded to improve the startup performance.
var StringDecoder;
var createReadableStreamAsyncIterator;
var from;
require('inherits')(Readable, Stream);
var errorOrDestroy = destroyImpl.errorOrDestroy;
var kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];
function prependListener(emitter, event, fn) {
  // Sadly this is not cacheable as some libraries bundle their own
  // event emitter implementation with them.
  if (typeof emitter.prependListener === 'function') return emitter.prependListener(event, fn);

  // This is a hack to make sure that our error handler is attached before any
  // userland ones.  NEVER DO THIS. This is here only because this code needs
  // to continue to work with older versions of Node.js that do not include
  // the prependListener() method. The goal is to eventually remove this hack.
  if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (Array.isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
}
function ReadableState(options, stream, isDuplex) {
  Duplex = Duplex || require('./_stream_duplex');
  options = options || {};

  // Duplex streams are both readable and writable, but share
  // the same options object.
  // However, some cases require setting options to different
  // values for the readable and the writable sides of the duplex stream.
  // These options can be provided separately as readableXXX and writableXXX.
  if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex;

  // object stream flag. Used to make read(n) ignore n and to
  // make all the buffer merging and length checks go away
  this.objectMode = !!options.objectMode;
  if (isDuplex) this.objectMode = this.objectMode || !!options.readableObjectMode;

  // the point at which it stops calling _read() to fill the buffer
  // Note: 0 is a valid value, means "don't call _read preemptively ever"
  this.highWaterMark = getHighWaterMark(this, options, 'readableHighWaterMark', isDuplex);

  // A linked list is used to store data chunks instead of an array because the
  // linked list can remove elements from the beginning faster than
  // array.shift()
  this.buffer = new BufferList();
  this.length = 0;
  this.pipes = null;
  this.pipesCount = 0;
  this.flowing = null;
  this.ended = false;
  this.endEmitted = false;
  this.reading = false;

  // a flag to be able to tell if the event 'readable'/'data' is emitted
  // immediately, or on a later tick.  We set this to true at first, because
  // any actions that shouldn't happen until "later" should generally also
  // not happen before the first read call.
  this.sync = true;

  // whenever we return null, then we set a flag to say
  // that we're awaiting a 'readable' event emission.
  this.needReadable = false;
  this.emittedReadable = false;
  this.readableListening = false;
  this.resumeScheduled = false;
  this.paused = true;

  // Should close be emitted on destroy. Defaults to true.
  this.emitClose = options.emitClose !== false;

  // Should .destroy() be called after 'end' (and potentially 'finish')
  this.autoDestroy = !!options.autoDestroy;

  // has it been destroyed
  this.destroyed = false;

  // Crypto is kind of old and crusty.  Historically, its default string
  // encoding is 'binary' so we have to make this configurable.
  // Everything else in the universe uses 'utf8', though.
  this.defaultEncoding = options.defaultEncoding || 'utf8';

  // the number of writers that are awaiting a drain event in .pipe()s
  this.awaitDrain = 0;

  // if true, a maybeReadMore has been scheduled
  this.readingMore = false;
  this.decoder = null;
  this.encoding = null;
  if (options.encoding) {
    if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
    this.decoder = new StringDecoder(options.encoding);
    this.encoding = options.encoding;
  }
}
function Readable(options) {
  Duplex = Duplex || require('./_stream_duplex');
  if (!(this instanceof Readable)) return new Readable(options);

  // Checking for a Stream.Duplex instance is faster here instead of inside
  // the ReadableState constructor, at least with V8 6.5
  var isDuplex = this instanceof Duplex;
  this._readableState = new ReadableState(options, this, isDuplex);

  // legacy
  this.readable = true;
  if (options) {
    if (typeof options.read === 'function') this._read = options.read;
    if (typeof options.destroy === 'function') this._destroy = options.destroy;
  }
  Stream.call(this);
}
Object.defineProperty(Readable.prototype, 'destroyed', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    if (this._readableState === undefined) {
      return false;
    }
    return this._readableState.destroyed;
  },
  set: function set(value) {
    // we ignore the value if the stream
    // has not been initialized yet
    if (!this._readableState) {
      return;
    }

    // backward compatibility, the user is explicitly
    // managing destroyed
    this._readableState.destroyed = value;
  }
});
Readable.prototype.destroy = destroyImpl.destroy;
Readable.prototype._undestroy = destroyImpl.undestroy;
Readable.prototype._destroy = function (err, cb) {
  cb(err);
};

// Manually shove something into the read() buffer.
// This returns true if the highWaterMark has not been hit yet,
// similar to how Writable.write() returns true if you should
// write() some more.
Readable.prototype.push = function (chunk, encoding) {
  var state = this._readableState;
  var skipChunkCheck;
  if (!state.objectMode) {
    if (typeof chunk === 'string') {
      encoding = encoding || state.defaultEncoding;
      if (encoding !== state.encoding) {
        chunk = Buffer.from(chunk, encoding);
        encoding = '';
      }
      skipChunkCheck = true;
    }
  } else {
    skipChunkCheck = true;
  }
  return readableAddChunk(this, chunk, encoding, false, skipChunkCheck);
};

// Unshift should *always* be something directly out of read()
Readable.prototype.unshift = function (chunk) {
  return readableAddChunk(this, chunk, null, true, false);
};
function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
  debug('readableAddChunk', chunk);
  var state = stream._readableState;
  if (chunk === null) {
    state.reading = false;
    onEofChunk(stream, state);
  } else {
    var er;
    if (!skipChunkCheck) er = chunkInvalid(state, chunk);
    if (er) {
      errorOrDestroy(stream, er);
    } else if (state.objectMode || chunk && chunk.length > 0) {
      if (typeof chunk !== 'string' && !state.objectMode && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
        chunk = _uint8ArrayToBuffer(chunk);
      }
      if (addToFront) {
        if (state.endEmitted) errorOrDestroy(stream, new ERR_STREAM_UNSHIFT_AFTER_END_EVENT());else addChunk(stream, state, chunk, true);
      } else if (state.ended) {
        errorOrDestroy(stream, new ERR_STREAM_PUSH_AFTER_EOF());
      } else if (state.destroyed) {
        return false;
      } else {
        state.reading = false;
        if (state.decoder && !encoding) {
          chunk = state.decoder.write(chunk);
          if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false);else maybeReadMore(stream, state);
        } else {
          addChunk(stream, state, chunk, false);
        }
      }
    } else if (!addToFront) {
      state.reading = false;
      maybeReadMore(stream, state);
    }
  }

  // We can push more data if we are below the highWaterMark.
  // Also, if we have no data yet, we can stand some more bytes.
  // This is to work around cases where hwm=0, such as the repl.
  return !state.ended && (state.length < state.highWaterMark || state.length === 0);
}
function addChunk(stream, state, chunk, addToFront) {
  if (state.flowing && state.length === 0 && !state.sync) {
    state.awaitDrain = 0;
    stream.emit('data', chunk);
  } else {
    // update the buffer info.
    state.length += state.objectMode ? 1 : chunk.length;
    if (addToFront) state.buffer.unshift(chunk);else state.buffer.push(chunk);
    if (state.needReadable) emitReadable(stream);
  }
  maybeReadMore(stream, state);
}
function chunkInvalid(state, chunk) {
  var er;
  if (!_isUint8Array(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
    er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer', 'Uint8Array'], chunk);
  }
  return er;
}
Readable.prototype.isPaused = function () {
  return this._readableState.flowing === false;
};

// backwards compatibility.
Readable.prototype.setEncoding = function (enc) {
  if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
  var decoder = new StringDecoder(enc);
  this._readableState.decoder = decoder;
  // If setEncoding(null), decoder.encoding equals utf8
  this._readableState.encoding = this._readableState.decoder.encoding;

  // Iterate over current buffer to convert already stored Buffers:
  var p = this._readableState.buffer.head;
  var content = '';
  while (p !== null) {
    content += decoder.write(p.data);
    p = p.next;
  }
  this._readableState.buffer.clear();
  if (content !== '') this._readableState.buffer.push(content);
  this._readableState.length = content.length;
  return this;
};

// Don't raise the hwm > 1GB
var MAX_HWM = 0x40000000;
function computeNewHighWaterMark(n) {
  if (n >= MAX_HWM) {
    // TODO(ronag): Throw ERR_VALUE_OUT_OF_RANGE.
    n = MAX_HWM;
  } else {
    // Get the next highest power of 2 to prevent increasing hwm excessively in
    // tiny amounts
    n--;
    n |= n >>> 1;
    n |= n >>> 2;
    n |= n >>> 4;
    n |= n >>> 8;
    n |= n >>> 16;
    n++;
  }
  return n;
}

// This function is designed to be inlinable, so please take care when making
// changes to the function body.
function howMuchToRead(n, state) {
  if (n <= 0 || state.length === 0 && state.ended) return 0;
  if (state.objectMode) return 1;
  if (n !== n) {
    // Only flow one buffer at a time
    if (state.flowing && state.length) return state.buffer.head.data.length;else return state.length;
  }
  // If we're asking for more than the current hwm, then raise the hwm.
  if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
  if (n <= state.length) return n;
  // Don't have enough
  if (!state.ended) {
    state.needReadable = true;
    return 0;
  }
  return state.length;
}

// you can override either this method, or the async _read(n) below.
Readable.prototype.read = function (n) {
  debug('read', n);
  n = parseInt(n, 10);
  var state = this._readableState;
  var nOrig = n;
  if (n !== 0) state.emittedReadable = false;

  // if we're doing read(0) to trigger a readable event, but we
  // already have a bunch of data in the buffer, then just trigger
  // the 'readable' event and move on.
  if (n === 0 && state.needReadable && ((state.highWaterMark !== 0 ? state.length >= state.highWaterMark : state.length > 0) || state.ended)) {
    debug('read: emitReadable', state.length, state.ended);
    if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
    return null;
  }
  n = howMuchToRead(n, state);

  // if we've ended, and we're now clear, then finish it up.
  if (n === 0 && state.ended) {
    if (state.length === 0) endReadable(this);
    return null;
  }

  // All the actual chunk generation logic needs to be
  // *below* the call to _read.  The reason is that in certain
  // synthetic stream cases, such as passthrough streams, _read
  // may be a completely synchronous operation which may change
  // the state of the read buffer, providing enough data when
  // before there was *not* enough.
  //
  // So, the steps are:
  // 1. Figure out what the state of things will be after we do
  // a read from the buffer.
  //
  // 2. If that resulting state will trigger a _read, then call _read.
  // Note that this may be asynchronous, or synchronous.  Yes, it is
  // deeply ugly to write APIs this way, but that still doesn't mean
  // that the Readable class should behave improperly, as streams are
  // designed to be sync/async agnostic.
  // Take note if the _read call is sync or async (ie, if the read call
  // has returned yet), so that we know whether or not it's safe to emit
  // 'readable' etc.
  //
  // 3. Actually pull the requested chunks out of the buffer and return.

  // if we need a readable event, then we need to do some reading.
  var doRead = state.needReadable;
  debug('need readable', doRead);

  // if we currently have less than the highWaterMark, then also read some
  if (state.length === 0 || state.length - n < state.highWaterMark) {
    doRead = true;
    debug('length less than watermark', doRead);
  }

  // however, if we've ended, then there's no point, and if we're already
  // reading, then it's unnecessary.
  if (state.ended || state.reading) {
    doRead = false;
    debug('reading or ended', doRead);
  } else if (doRead) {
    debug('do read');
    state.reading = true;
    state.sync = true;
    // if the length is currently zero, then we *need* a readable event.
    if (state.length === 0) state.needReadable = true;
    // call internal read method
    this._read(state.highWaterMark);
    state.sync = false;
    // If _read pushed data synchronously, then `reading` will be false,
    // and we need to re-evaluate how much data we can return to the user.
    if (!state.reading) n = howMuchToRead(nOrig, state);
  }
  var ret;
  if (n > 0) ret = fromList(n, state);else ret = null;
  if (ret === null) {
    state.needReadable = state.length <= state.highWaterMark;
    n = 0;
  } else {
    state.length -= n;
    state.awaitDrain = 0;
  }
  if (state.length === 0) {
    // If we have nothing in the buffer, then we want to know
    // as soon as we *do* get something into the buffer.
    if (!state.ended) state.needReadable = true;

    // If we tried to read() past the EOF, then emit end on the next tick.
    if (nOrig !== n && state.ended) endReadable(this);
  }
  if (ret !== null) this.emit('data', ret);
  return ret;
};
function onEofChunk(stream, state) {
  debug('onEofChunk');
  if (state.ended) return;
  if (state.decoder) {
    var chunk = state.decoder.end();
    if (chunk && chunk.length) {
      state.buffer.push(chunk);
      state.length += state.objectMode ? 1 : chunk.length;
    }
  }
  state.ended = true;
  if (state.sync) {
    // if we are sync, wait until next tick to emit the data.
    // Otherwise we risk emitting data in the flow()
    // the readable code triggers during a read() call
    emitReadable(stream);
  } else {
    // emit 'readable' now to make sure it gets picked up.
    state.needReadable = false;
    if (!state.emittedReadable) {
      state.emittedReadable = true;
      emitReadable_(stream);
    }
  }
}

// Don't emit readable right away in sync mode, because this can trigger
// another read() call => stack overflow.  This way, it might trigger
// a nextTick recursion warning, but that's not so bad.
function emitReadable(stream) {
  var state = stream._readableState;
  debug('emitReadable', state.needReadable, state.emittedReadable);
  state.needReadable = false;
  if (!state.emittedReadable) {
    debug('emitReadable', state.flowing);
    state.emittedReadable = true;
    process.nextTick(emitReadable_, stream);
  }
}
function emitReadable_(stream) {
  var state = stream._readableState;
  debug('emitReadable_', state.destroyed, state.length, state.ended);
  if (!state.destroyed && (state.length || state.ended)) {
    stream.emit('readable');
    state.emittedReadable = false;
  }

  // The stream needs another readable event if
  // 1. It is not flowing, as the flow mechanism will take
  //    care of it.
  // 2. It is not ended.
  // 3. It is below the highWaterMark, so we can schedule
  //    another readable later.
  state.needReadable = !state.flowing && !state.ended && state.length <= state.highWaterMark;
  flow(stream);
}

// at this point, the user has presumably seen the 'readable' event,
// and called read() to consume some data.  that may have triggered
// in turn another _read(n) call, in which case reading = true if
// it's in progress.
// However, if we're not ended, or reading, and the length < hwm,
// then go ahead and try to read some more preemptively.
function maybeReadMore(stream, state) {
  if (!state.readingMore) {
    state.readingMore = true;
    process.nextTick(maybeReadMore_, stream, state);
  }
}
function maybeReadMore_(stream, state) {
  // Attempt to read more data if we should.
  //
  // The conditions for reading more data are (one of):
  // - Not enough data buffered (state.length < state.highWaterMark). The loop
  //   is responsible for filling the buffer with enough data if such data
  //   is available. If highWaterMark is 0 and we are not in the flowing mode
  //   we should _not_ attempt to buffer any extra data. We'll get more data
  //   when the stream consumer calls read() instead.
  // - No data in the buffer, and the stream is in flowing mode. In this mode
  //   the loop below is responsible for ensuring read() is called. Failing to
  //   call read here would abort the flow and there's no other mechanism for
  //   continuing the flow if the stream consumer has just subscribed to the
  //   'data' event.
  //
  // In addition to the above conditions to keep reading data, the following
  // conditions prevent the data from being read:
  // - The stream has ended (state.ended).
  // - There is already a pending 'read' operation (state.reading). This is a
  //   case where the the stream has called the implementation defined _read()
  //   method, but they are processing the call asynchronously and have _not_
  //   called push() with new data. In this case we skip performing more
  //   read()s. The execution ends in this method again after the _read() ends
  //   up calling push() with more data.
  while (!state.reading && !state.ended && (state.length < state.highWaterMark || state.flowing && state.length === 0)) {
    var len = state.length;
    debug('maybeReadMore read 0');
    stream.read(0);
    if (len === state.length)
      // didn't get any data, stop spinning.
      break;
  }
  state.readingMore = false;
}

// abstract method.  to be overridden in specific implementation classes.
// call cb(er, data) where data is <= n in length.
// for virtual (non-string, non-buffer) streams, "length" is somewhat
// arbitrary, and perhaps not very meaningful.
Readable.prototype._read = function (n) {
  errorOrDestroy(this, new ERR_METHOD_NOT_IMPLEMENTED('_read()'));
};
Readable.prototype.pipe = function (dest, pipeOpts) {
  var src = this;
  var state = this._readableState;
  switch (state.pipesCount) {
    case 0:
      state.pipes = dest;
      break;
    case 1:
      state.pipes = [state.pipes, dest];
      break;
    default:
      state.pipes.push(dest);
      break;
  }
  state.pipesCount += 1;
  debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);
  var doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr;
  var endFn = doEnd ? onend : unpipe;
  if (state.endEmitted) process.nextTick(endFn);else src.once('end', endFn);
  dest.on('unpipe', onunpipe);
  function onunpipe(readable, unpipeInfo) {
    debug('onunpipe');
    if (readable === src) {
      if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
        unpipeInfo.hasUnpiped = true;
        cleanup();
      }
    }
  }
  function onend() {
    debug('onend');
    dest.end();
  }

  // when the dest drains, it reduces the awaitDrain counter
  // on the source.  This would be more elegant with a .once()
  // handler in flow(), but adding and removing repeatedly is
  // too slow.
  var ondrain = pipeOnDrain(src);
  dest.on('drain', ondrain);
  var cleanedUp = false;
  function cleanup() {
    debug('cleanup');
    // cleanup event handlers once the pipe is broken
    dest.removeListener('close', onclose);
    dest.removeListener('finish', onfinish);
    dest.removeListener('drain', ondrain);
    dest.removeListener('error', onerror);
    dest.removeListener('unpipe', onunpipe);
    src.removeListener('end', onend);
    src.removeListener('end', unpipe);
    src.removeListener('data', ondata);
    cleanedUp = true;

    // if the reader is waiting for a drain event from this
    // specific writer, then it would cause it to never start
    // flowing again.
    // So, if this is awaiting a drain, then we just call it now.
    // If we don't know, then assume that we are waiting for one.
    if (state.awaitDrain && (!dest._writableState || dest._writableState.needDrain)) ondrain();
  }
  src.on('data', ondata);
  function ondata(chunk) {
    debug('ondata');
    var ret = dest.write(chunk);
    debug('dest.write', ret);
    if (ret === false) {
      // If the user unpiped during `dest.write()`, it is possible
      // to get stuck in a permanently paused state if that write
      // also returned false.
      // => Check whether `dest` is still a piping destination.
      if ((state.pipesCount === 1 && state.pipes === dest || state.pipesCount > 1 && indexOf(state.pipes, dest) !== -1) && !cleanedUp) {
        debug('false write response, pause', state.awaitDrain);
        state.awaitDrain++;
      }
      src.pause();
    }
  }

  // if the dest has an error, then stop piping into it.
  // however, don't suppress the throwing behavior for this.
  function onerror(er) {
    debug('onerror', er);
    unpipe();
    dest.removeListener('error', onerror);
    if (EElistenerCount(dest, 'error') === 0) errorOrDestroy(dest, er);
  }

  // Make sure our error handler is attached before userland ones.
  prependListener(dest, 'error', onerror);

  // Both close and finish should trigger unpipe, but only once.
  function onclose() {
    dest.removeListener('finish', onfinish);
    unpipe();
  }
  dest.once('close', onclose);
  function onfinish() {
    debug('onfinish');
    dest.removeListener('close', onclose);
    unpipe();
  }
  dest.once('finish', onfinish);
  function unpipe() {
    debug('unpipe');
    src.unpipe(dest);
  }

  // tell the dest that it's being piped to
  dest.emit('pipe', src);

  // start the flow if it hasn't been started already.
  if (!state.flowing) {
    debug('pipe resume');
    src.resume();
  }
  return dest;
};
function pipeOnDrain(src) {
  return function pipeOnDrainFunctionResult() {
    var state = src._readableState;
    debug('pipeOnDrain', state.awaitDrain);
    if (state.awaitDrain) state.awaitDrain--;
    if (state.awaitDrain === 0 && EElistenerCount(src, 'data')) {
      state.flowing = true;
      flow(src);
    }
  };
}
Readable.prototype.unpipe = function (dest) {
  var state = this._readableState;
  var unpipeInfo = {
    hasUnpiped: false
  };

  // if we're not piping anywhere, then do nothing.
  if (state.pipesCount === 0) return this;

  // just one destination.  most common case.
  if (state.pipesCount === 1) {
    // passed in one, but it's not the right one.
    if (dest && dest !== state.pipes) return this;
    if (!dest) dest = state.pipes;

    // got a match.
    state.pipes = null;
    state.pipesCount = 0;
    state.flowing = false;
    if (dest) dest.emit('unpipe', this, unpipeInfo);
    return this;
  }

  // slow case. multiple pipe destinations.

  if (!dest) {
    // remove all.
    var dests = state.pipes;
    var len = state.pipesCount;
    state.pipes = null;
    state.pipesCount = 0;
    state.flowing = false;
    for (var i = 0; i < len; i++) dests[i].emit('unpipe', this, {
      hasUnpiped: false
    });
    return this;
  }

  // try to find the right one.
  var index = indexOf(state.pipes, dest);
  if (index === -1) return this;
  state.pipes.splice(index, 1);
  state.pipesCount -= 1;
  if (state.pipesCount === 1) state.pipes = state.pipes[0];
  dest.emit('unpipe', this, unpipeInfo);
  return this;
};

// set up data events if they are asked for
// Ensure readable listeners eventually get something
Readable.prototype.on = function (ev, fn) {
  var res = Stream.prototype.on.call(this, ev, fn);
  var state = this._readableState;
  if (ev === 'data') {
    // update readableListening so that resume() may be a no-op
    // a few lines down. This is needed to support once('readable').
    state.readableListening = this.listenerCount('readable') > 0;

    // Try start flowing on next tick if stream isn't explicitly paused
    if (state.flowing !== false) this.resume();
  } else if (ev === 'readable') {
    if (!state.endEmitted && !state.readableListening) {
      state.readableListening = state.needReadable = true;
      state.flowing = false;
      state.emittedReadable = false;
      debug('on readable', state.length, state.reading);
      if (state.length) {
        emitReadable(this);
      } else if (!state.reading) {
        process.nextTick(nReadingNextTick, this);
      }
    }
  }
  return res;
};
Readable.prototype.addListener = Readable.prototype.on;
Readable.prototype.removeListener = function (ev, fn) {
  var res = Stream.prototype.removeListener.call(this, ev, fn);
  if (ev === 'readable') {
    // We need to check if there is someone still listening to
    // readable and reset the state. However this needs to happen
    // after readable has been emitted but before I/O (nextTick) to
    // support once('readable', fn) cycles. This means that calling
    // resume within the same tick will have no
    // effect.
    process.nextTick(updateReadableListening, this);
  }
  return res;
};
Readable.prototype.removeAllListeners = function (ev) {
  var res = Stream.prototype.removeAllListeners.apply(this, arguments);
  if (ev === 'readable' || ev === undefined) {
    // We need to check if there is someone still listening to
    // readable and reset the state. However this needs to happen
    // after readable has been emitted but before I/O (nextTick) to
    // support once('readable', fn) cycles. This means that calling
    // resume within the same tick will have no
    // effect.
    process.nextTick(updateReadableListening, this);
  }
  return res;
};
function updateReadableListening(self) {
  var state = self._readableState;
  state.readableListening = self.listenerCount('readable') > 0;
  if (state.resumeScheduled && !state.paused) {
    // flowing needs to be set to true now, otherwise
    // the upcoming resume will not flow.
    state.flowing = true;

    // crude way to check if we should resume
  } else if (self.listenerCount('data') > 0) {
    self.resume();
  }
}
function nReadingNextTick(self) {
  debug('readable nexttick read 0');
  self.read(0);
}

// pause() and resume() are remnants of the legacy readable stream API
// If the user uses them, then switch into old mode.
Readable.prototype.resume = function () {
  var state = this._readableState;
  if (!state.flowing) {
    debug('resume');
    // we flow only if there is no one listening
    // for readable, but we still have to call
    // resume()
    state.flowing = !state.readableListening;
    resume(this, state);
  }
  state.paused = false;
  return this;
};
function resume(stream, state) {
  if (!state.resumeScheduled) {
    state.resumeScheduled = true;
    process.nextTick(resume_, stream, state);
  }
}
function resume_(stream, state) {
  debug('resume', state.reading);
  if (!state.reading) {
    stream.read(0);
  }
  state.resumeScheduled = false;
  stream.emit('resume');
  flow(stream);
  if (state.flowing && !state.reading) stream.read(0);
}
Readable.prototype.pause = function () {
  debug('call pause flowing=%j', this._readableState.flowing);
  if (this._readableState.flowing !== false) {
    debug('pause');
    this._readableState.flowing = false;
    this.emit('pause');
  }
  this._readableState.paused = true;
  return this;
};
function flow(stream) {
  var state = stream._readableState;
  debug('flow', state.flowing);
  while (state.flowing && stream.read() !== null);
}

// wrap an old-style stream as the async data source.
// This is *not* part of the readable stream interface.
// It is an ugly unfortunate mess of history.
Readable.prototype.wrap = function (stream) {
  var _this = this;
  var state = this._readableState;
  var paused = false;
  stream.on('end', function () {
    debug('wrapped end');
    if (state.decoder && !state.ended) {
      var chunk = state.decoder.end();
      if (chunk && chunk.length) _this.push(chunk);
    }
    _this.push(null);
  });
  stream.on('data', function (chunk) {
    debug('wrapped data');
    if (state.decoder) chunk = state.decoder.write(chunk);

    // don't skip over falsy values in objectMode
    if (state.objectMode && (chunk === null || chunk === undefined)) return;else if (!state.objectMode && (!chunk || !chunk.length)) return;
    var ret = _this.push(chunk);
    if (!ret) {
      paused = true;
      stream.pause();
    }
  });

  // proxy all the other methods.
  // important when wrapping filters and duplexes.
  for (var i in stream) {
    if (this[i] === undefined && typeof stream[i] === 'function') {
      this[i] = function methodWrap(method) {
        return function methodWrapReturnFunction() {
          return stream[method].apply(stream, arguments);
        };
      }(i);
    }
  }

  // proxy certain important events.
  for (var n = 0; n < kProxyEvents.length; n++) {
    stream.on(kProxyEvents[n], this.emit.bind(this, kProxyEvents[n]));
  }

  // when we try to consume some more bytes, simply unpause the
  // underlying stream.
  this._read = function (n) {
    debug('wrapped _read', n);
    if (paused) {
      paused = false;
      stream.resume();
    }
  };
  return this;
};
if (typeof Symbol === 'function') {
  Readable.prototype[Symbol.asyncIterator] = function () {
    if (createReadableStreamAsyncIterator === undefined) {
      createReadableStreamAsyncIterator = require('./internal/streams/async_iterator');
    }
    return createReadableStreamAsyncIterator(this);
  };
}
Object.defineProperty(Readable.prototype, 'readableHighWaterMark', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._readableState.highWaterMark;
  }
});
Object.defineProperty(Readable.prototype, 'readableBuffer', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._readableState && this._readableState.buffer;
  }
});
Object.defineProperty(Readable.prototype, 'readableFlowing', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._readableState.flowing;
  },
  set: function set(state) {
    if (this._readableState) {
      this._readableState.flowing = state;
    }
  }
});

// exposed for testing purposes only.
Readable._fromList = fromList;
Object.defineProperty(Readable.prototype, 'readableLength', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._readableState.length;
  }
});

// Pluck off n bytes from an array of buffers.
// Length is the combined lengths of all the buffers in the list.
// This function is designed to be inlinable, so please take care when making
// changes to the function body.
function fromList(n, state) {
  // nothing buffered
  if (state.length === 0) return null;
  var ret;
  if (state.objectMode) ret = state.buffer.shift();else if (!n || n >= state.length) {
    // read it all, truncate the list
    if (state.decoder) ret = state.buffer.join('');else if (state.buffer.length === 1) ret = state.buffer.first();else ret = state.buffer.concat(state.length);
    state.buffer.clear();
  } else {
    // read part of list
    ret = state.buffer.consume(n, state.decoder);
  }
  return ret;
}
function endReadable(stream) {
  var state = stream._readableState;
  debug('endReadable', state.endEmitted);
  if (!state.endEmitted) {
    state.ended = true;
    process.nextTick(endReadableNT, state, stream);
  }
}
function endReadableNT(state, stream) {
  debug('endReadableNT', state.endEmitted, state.length);

  // Check that we didn't get one last unshift.
  if (!state.endEmitted && state.length === 0) {
    state.endEmitted = true;
    stream.readable = false;
    stream.emit('end');
    if (state.autoDestroy) {
      // In case of duplex streams we need a way to detect
      // if the writable side is ready for autoDestroy as well
      var wState = stream._writableState;
      if (!wState || wState.autoDestroy && wState.finished) {
        stream.destroy();
      }
    }
  }
}
if (typeof Symbol === 'function') {
  Readable.from = function (iterable, opts) {
    if (from === undefined) {
      from = require('./internal/streams/from');
    }
    return from(Readable, iterable, opts);
  };
}
function indexOf(xs, x) {
  for (var i = 0, l = xs.length; i < l; i++) {
    if (xs[i] === x) return i;
  }
  return -1;
}
}).call(this)}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"../errors":13,"./_stream_duplex":14,"./internal/streams/async_iterator":19,"./internal/streams/buffer_list":20,"./internal/streams/destroy":21,"./internal/streams/from":23,"./internal/streams/state":25,"./internal/streams/stream":26,"_process":56,"buffer":51,"events":52,"inherits":10,"string_decoder/":38,"util":50}],17:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// a transform stream is a readable/writable stream where you do
// something with the data.  Sometimes it's called a "filter",
// but that's not a great name for it, since that implies a thing where
// some bits pass through, and others are simply ignored.  (That would
// be a valid example of a transform, of course.)
//
// While the output is causally related to the input, it's not a
// necessarily symmetric or synchronous transformation.  For example,
// a zlib stream might take multiple plain-text writes(), and then
// emit a single compressed chunk some time in the future.
//
// Here's how this works:
//
// The Transform stream has all the aspects of the readable and writable
// stream classes.  When you write(chunk), that calls _write(chunk,cb)
// internally, and returns false if there's a lot of pending writes
// buffered up.  When you call read(), that calls _read(n) until
// there's enough pending readable data buffered up.
//
// In a transform stream, the written data is placed in a buffer.  When
// _read(n) is called, it transforms the queued up data, calling the
// buffered _write cb's as it consumes chunks.  If consuming a single
// written chunk would result in multiple output chunks, then the first
// outputted bit calls the readcb, and subsequent chunks just go into
// the read buffer, and will cause it to emit 'readable' if necessary.
//
// This way, back-pressure is actually determined by the reading side,
// since _read has to be called to start processing a new chunk.  However,
// a pathological inflate type of transform can cause excessive buffering
// here.  For example, imagine a stream where every byte of input is
// interpreted as an integer from 0-255, and then results in that many
// bytes of output.  Writing the 4 bytes {ff,ff,ff,ff} would result in
// 1kb of data being output.  In this case, you could write a very small
// amount of input, and end up with a very large amount of output.  In
// such a pathological inflating mechanism, there'd be no way to tell
// the system to stop doing the transform.  A single 4MB write could
// cause the system to run out of memory.
//
// However, even in such a pathological case, only a single written chunk
// would be consumed, and then the rest would wait (un-transformed) until
// the results of the previous transformed chunk were consumed.

'use strict';

module.exports = Transform;
var _require$codes = require('../errors').codes,
  ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
  ERR_MULTIPLE_CALLBACK = _require$codes.ERR_MULTIPLE_CALLBACK,
  ERR_TRANSFORM_ALREADY_TRANSFORMING = _require$codes.ERR_TRANSFORM_ALREADY_TRANSFORMING,
  ERR_TRANSFORM_WITH_LENGTH_0 = _require$codes.ERR_TRANSFORM_WITH_LENGTH_0;
var Duplex = require('./_stream_duplex');
require('inherits')(Transform, Duplex);
function afterTransform(er, data) {
  var ts = this._transformState;
  ts.transforming = false;
  var cb = ts.writecb;
  if (cb === null) {
    return this.emit('error', new ERR_MULTIPLE_CALLBACK());
  }
  ts.writechunk = null;
  ts.writecb = null;
  if (data != null)
    // single equals check for both `null` and `undefined`
    this.push(data);
  cb(er);
  var rs = this._readableState;
  rs.reading = false;
  if (rs.needReadable || rs.length < rs.highWaterMark) {
    this._read(rs.highWaterMark);
  }
}
function Transform(options) {
  if (!(this instanceof Transform)) return new Transform(options);
  Duplex.call(this, options);
  this._transformState = {
    afterTransform: afterTransform.bind(this),
    needTransform: false,
    transforming: false,
    writecb: null,
    writechunk: null,
    writeencoding: null
  };

  // start out asking for a readable event once data is transformed.
  this._readableState.needReadable = true;

  // we have implemented the _read method, and done the other things
  // that Readable wants before the first _read call, so unset the
  // sync guard flag.
  this._readableState.sync = false;
  if (options) {
    if (typeof options.transform === 'function') this._transform = options.transform;
    if (typeof options.flush === 'function') this._flush = options.flush;
  }

  // When the writable side finishes, then flush out anything remaining.
  this.on('prefinish', prefinish);
}
function prefinish() {
  var _this = this;
  if (typeof this._flush === 'function' && !this._readableState.destroyed) {
    this._flush(function (er, data) {
      done(_this, er, data);
    });
  } else {
    done(this, null, null);
  }
}
Transform.prototype.push = function (chunk, encoding) {
  this._transformState.needTransform = false;
  return Duplex.prototype.push.call(this, chunk, encoding);
};

// This is the part where you do stuff!
// override this function in implementation classes.
// 'chunk' is an input chunk.
//
// Call `push(newChunk)` to pass along transformed output
// to the readable side.  You may call 'push' zero or more times.
//
// Call `cb(err)` when you are done with this chunk.  If you pass
// an error, then that'll put the hurt on the whole operation.  If you
// never call cb(), then you'll never get another chunk.
Transform.prototype._transform = function (chunk, encoding, cb) {
  cb(new ERR_METHOD_NOT_IMPLEMENTED('_transform()'));
};
Transform.prototype._write = function (chunk, encoding, cb) {
  var ts = this._transformState;
  ts.writecb = cb;
  ts.writechunk = chunk;
  ts.writeencoding = encoding;
  if (!ts.transforming) {
    var rs = this._readableState;
    if (ts.needTransform || rs.needReadable || rs.length < rs.highWaterMark) this._read(rs.highWaterMark);
  }
};

// Doesn't matter what the args are here.
// _transform does all the work.
// That we got here means that the readable side wants more data.
Transform.prototype._read = function (n) {
  var ts = this._transformState;
  if (ts.writechunk !== null && !ts.transforming) {
    ts.transforming = true;
    this._transform(ts.writechunk, ts.writeencoding, ts.afterTransform);
  } else {
    // mark that we need a transform, so that any data that comes in
    // will get processed, now that we've asked for it.
    ts.needTransform = true;
  }
};
Transform.prototype._destroy = function (err, cb) {
  Duplex.prototype._destroy.call(this, err, function (err2) {
    cb(err2);
  });
};
function done(stream, er, data) {
  if (er) return stream.emit('error', er);
  if (data != null)
    // single equals check for both `null` and `undefined`
    stream.push(data);

  // TODO(BridgeAR): Write a test for these two error cases
  // if there's nothing in the write buffer, then that means
  // that nothing more will ever be provided
  if (stream._writableState.length) throw new ERR_TRANSFORM_WITH_LENGTH_0();
  if (stream._transformState.transforming) throw new ERR_TRANSFORM_ALREADY_TRANSFORMING();
  return stream.push(null);
}
},{"../errors":13,"./_stream_duplex":14,"inherits":10}],18:[function(require,module,exports){
(function (process,global){(function (){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

// A bit simpler than readable streams.
// Implement an async ._write(chunk, encoding, cb), and it'll handle all
// the drain event emission and buffering.

'use strict';

module.exports = Writable;

/* <replacement> */
function WriteReq(chunk, encoding, cb) {
  this.chunk = chunk;
  this.encoding = encoding;
  this.callback = cb;
  this.next = null;
}

// It seems a linked list but it is not
// there will be only 2 of these for each stream
function CorkedRequest(state) {
  var _this = this;
  this.next = null;
  this.entry = null;
  this.finish = function () {
    onCorkedFinish(_this, state);
  };
}
/* </replacement> */

/*<replacement>*/
var Duplex;
/*</replacement>*/

Writable.WritableState = WritableState;

/*<replacement>*/
var internalUtil = {
  deprecate: require('util-deprecate')
};
/*</replacement>*/

/*<replacement>*/
var Stream = require('./internal/streams/stream');
/*</replacement>*/

var Buffer = require('buffer').Buffer;
var OurUint8Array = (typeof global !== 'undefined' ? global : typeof window !== 'undefined' ? window : typeof self !== 'undefined' ? self : {}).Uint8Array || function () {};
function _uint8ArrayToBuffer(chunk) {
  return Buffer.from(chunk);
}
function _isUint8Array(obj) {
  return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
}
var destroyImpl = require('./internal/streams/destroy');
var _require = require('./internal/streams/state'),
  getHighWaterMark = _require.getHighWaterMark;
var _require$codes = require('../errors').codes,
  ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
  ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
  ERR_MULTIPLE_CALLBACK = _require$codes.ERR_MULTIPLE_CALLBACK,
  ERR_STREAM_CANNOT_PIPE = _require$codes.ERR_STREAM_CANNOT_PIPE,
  ERR_STREAM_DESTROYED = _require$codes.ERR_STREAM_DESTROYED,
  ERR_STREAM_NULL_VALUES = _require$codes.ERR_STREAM_NULL_VALUES,
  ERR_STREAM_WRITE_AFTER_END = _require$codes.ERR_STREAM_WRITE_AFTER_END,
  ERR_UNKNOWN_ENCODING = _require$codes.ERR_UNKNOWN_ENCODING;
var errorOrDestroy = destroyImpl.errorOrDestroy;
require('inherits')(Writable, Stream);
function nop() {}
function WritableState(options, stream, isDuplex) {
  Duplex = Duplex || require('./_stream_duplex');
  options = options || {};

  // Duplex streams are both readable and writable, but share
  // the same options object.
  // However, some cases require setting options to different
  // values for the readable and the writable sides of the duplex stream,
  // e.g. options.readableObjectMode vs. options.writableObjectMode, etc.
  if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex;

  // object stream flag to indicate whether or not this stream
  // contains buffers or objects.
  this.objectMode = !!options.objectMode;
  if (isDuplex) this.objectMode = this.objectMode || !!options.writableObjectMode;

  // the point at which write() starts returning false
  // Note: 0 is a valid value, means that we always return false if
  // the entire buffer is not flushed immediately on write()
  this.highWaterMark = getHighWaterMark(this, options, 'writableHighWaterMark', isDuplex);

  // if _final has been called
  this.finalCalled = false;

  // drain event flag.
  this.needDrain = false;
  // at the start of calling end()
  this.ending = false;
  // when end() has been called, and returned
  this.ended = false;
  // when 'finish' is emitted
  this.finished = false;

  // has it been destroyed
  this.destroyed = false;

  // should we decode strings into buffers before passing to _write?
  // this is here so that some node-core streams can optimize string
  // handling at a lower level.
  var noDecode = options.decodeStrings === false;
  this.decodeStrings = !noDecode;

  // Crypto is kind of old and crusty.  Historically, its default string
  // encoding is 'binary' so we have to make this configurable.
  // Everything else in the universe uses 'utf8', though.
  this.defaultEncoding = options.defaultEncoding || 'utf8';

  // not an actual buffer we keep track of, but a measurement
  // of how much we're waiting to get pushed to some underlying
  // socket or file.
  this.length = 0;

  // a flag to see when we're in the middle of a write.
  this.writing = false;

  // when true all writes will be buffered until .uncork() call
  this.corked = 0;

  // a flag to be able to tell if the onwrite cb is called immediately,
  // or on a later tick.  We set this to true at first, because any
  // actions that shouldn't happen until "later" should generally also
  // not happen before the first write call.
  this.sync = true;

  // a flag to know if we're processing previously buffered items, which
  // may call the _write() callback in the same tick, so that we don't
  // end up in an overlapped onwrite situation.
  this.bufferProcessing = false;

  // the callback that's passed to _write(chunk,cb)
  this.onwrite = function (er) {
    onwrite(stream, er);
  };

  // the callback that the user supplies to write(chunk,encoding,cb)
  this.writecb = null;

  // the amount that is being written when _write is called.
  this.writelen = 0;
  this.bufferedRequest = null;
  this.lastBufferedRequest = null;

  // number of pending user-supplied write callbacks
  // this must be 0 before 'finish' can be emitted
  this.pendingcb = 0;

  // emit prefinish if the only thing we're waiting for is _write cbs
  // This is relevant for synchronous Transform streams
  this.prefinished = false;

  // True if the error was already emitted and should not be thrown again
  this.errorEmitted = false;

  // Should close be emitted on destroy. Defaults to true.
  this.emitClose = options.emitClose !== false;

  // Should .destroy() be called after 'finish' (and potentially 'end')
  this.autoDestroy = !!options.autoDestroy;

  // count buffered requests
  this.bufferedRequestCount = 0;

  // allocate the first CorkedRequest, there is always
  // one allocated and free to use, and we maintain at most two
  this.corkedRequestsFree = new CorkedRequest(this);
}
WritableState.prototype.getBuffer = function getBuffer() {
  var current = this.bufferedRequest;
  var out = [];
  while (current) {
    out.push(current);
    current = current.next;
  }
  return out;
};
(function () {
  try {
    Object.defineProperty(WritableState.prototype, 'buffer', {
      get: internalUtil.deprecate(function writableStateBufferGetter() {
        return this.getBuffer();
      }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.', 'DEP0003')
    });
  } catch (_) {}
})();

// Test _writableState for inheritance to account for Duplex streams,
// whose prototype chain only points to Readable.
var realHasInstance;
if (typeof Symbol === 'function' && Symbol.hasInstance && typeof Function.prototype[Symbol.hasInstance] === 'function') {
  realHasInstance = Function.prototype[Symbol.hasInstance];
  Object.defineProperty(Writable, Symbol.hasInstance, {
    value: function value(object) {
      if (realHasInstance.call(this, object)) return true;
      if (this !== Writable) return false;
      return object && object._writableState instanceof WritableState;
    }
  });
} else {
  realHasInstance = function realHasInstance(object) {
    return object instanceof this;
  };
}
function Writable(options) {
  Duplex = Duplex || require('./_stream_duplex');

  // Writable ctor is applied to Duplexes, too.
  // `realHasInstance` is necessary because using plain `instanceof`
  // would return false, as no `_writableState` property is attached.

  // Trying to use the custom `instanceof` for Writable here will also break the
  // Node.js LazyTransform implementation, which has a non-trivial getter for
  // `_writableState` that would lead to infinite recursion.

  // Checking for a Stream.Duplex instance is faster here instead of inside
  // the WritableState constructor, at least with V8 6.5
  var isDuplex = this instanceof Duplex;
  if (!isDuplex && !realHasInstance.call(Writable, this)) return new Writable(options);
  this._writableState = new WritableState(options, this, isDuplex);

  // legacy.
  this.writable = true;
  if (options) {
    if (typeof options.write === 'function') this._write = options.write;
    if (typeof options.writev === 'function') this._writev = options.writev;
    if (typeof options.destroy === 'function') this._destroy = options.destroy;
    if (typeof options.final === 'function') this._final = options.final;
  }
  Stream.call(this);
}

// Otherwise people can pipe Writable streams, which is just wrong.
Writable.prototype.pipe = function () {
  errorOrDestroy(this, new ERR_STREAM_CANNOT_PIPE());
};
function writeAfterEnd(stream, cb) {
  var er = new ERR_STREAM_WRITE_AFTER_END();
  // TODO: defer error events consistently everywhere, not just the cb
  errorOrDestroy(stream, er);
  process.nextTick(cb, er);
}

// Checks that a user-supplied chunk is valid, especially for the particular
// mode the stream is in. Currently this means that `null` is never accepted
// and undefined/non-string values are only allowed in object mode.
function validChunk(stream, state, chunk, cb) {
  var er;
  if (chunk === null) {
    er = new ERR_STREAM_NULL_VALUES();
  } else if (typeof chunk !== 'string' && !state.objectMode) {
    er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer'], chunk);
  }
  if (er) {
    errorOrDestroy(stream, er);
    process.nextTick(cb, er);
    return false;
  }
  return true;
}
Writable.prototype.write = function (chunk, encoding, cb) {
  var state = this._writableState;
  var ret = false;
  var isBuf = !state.objectMode && _isUint8Array(chunk);
  if (isBuf && !Buffer.isBuffer(chunk)) {
    chunk = _uint8ArrayToBuffer(chunk);
  }
  if (typeof encoding === 'function') {
    cb = encoding;
    encoding = null;
  }
  if (isBuf) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding;
  if (typeof cb !== 'function') cb = nop;
  if (state.ending) writeAfterEnd(this, cb);else if (isBuf || validChunk(this, state, chunk, cb)) {
    state.pendingcb++;
    ret = writeOrBuffer(this, state, isBuf, chunk, encoding, cb);
  }
  return ret;
};
Writable.prototype.cork = function () {
  this._writableState.corked++;
};
Writable.prototype.uncork = function () {
  var state = this._writableState;
  if (state.corked) {
    state.corked--;
    if (!state.writing && !state.corked && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state);
  }
};
Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) {
  // node::ParseEncoding() requires lower case.
  if (typeof encoding === 'string') encoding = encoding.toLowerCase();
  if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new ERR_UNKNOWN_ENCODING(encoding);
  this._writableState.defaultEncoding = encoding;
  return this;
};
Object.defineProperty(Writable.prototype, 'writableBuffer', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState && this._writableState.getBuffer();
  }
});
function decodeChunk(state, chunk, encoding) {
  if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') {
    chunk = Buffer.from(chunk, encoding);
  }
  return chunk;
}
Object.defineProperty(Writable.prototype, 'writableHighWaterMark', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState.highWaterMark;
  }
});

// if we're already writing something, then just put this
// in the queue, and wait our turn.  Otherwise, call _write
// If we return false, then we need a drain event, so set that flag.
function writeOrBuffer(stream, state, isBuf, chunk, encoding, cb) {
  if (!isBuf) {
    var newChunk = decodeChunk(state, chunk, encoding);
    if (chunk !== newChunk) {
      isBuf = true;
      encoding = 'buffer';
      chunk = newChunk;
    }
  }
  var len = state.objectMode ? 1 : chunk.length;
  state.length += len;
  var ret = state.length < state.highWaterMark;
  // we must ensure that previous needDrain will not be reset to false.
  if (!ret) state.needDrain = true;
  if (state.writing || state.corked) {
    var last = state.lastBufferedRequest;
    state.lastBufferedRequest = {
      chunk: chunk,
      encoding: encoding,
      isBuf: isBuf,
      callback: cb,
      next: null
    };
    if (last) {
      last.next = state.lastBufferedRequest;
    } else {
      state.bufferedRequest = state.lastBufferedRequest;
    }
    state.bufferedRequestCount += 1;
  } else {
    doWrite(stream, state, false, len, chunk, encoding, cb);
  }
  return ret;
}
function doWrite(stream, state, writev, len, chunk, encoding, cb) {
  state.writelen = len;
  state.writecb = cb;
  state.writing = true;
  state.sync = true;
  if (state.destroyed) state.onwrite(new ERR_STREAM_DESTROYED('write'));else if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite);
  state.sync = false;
}
function onwriteError(stream, state, sync, er, cb) {
  --state.pendingcb;
  if (sync) {
    // defer the callback if we are being called synchronously
    // to avoid piling up things on the stack
    process.nextTick(cb, er);
    // this can emit finish, and it will always happen
    // after error
    process.nextTick(finishMaybe, stream, state);
    stream._writableState.errorEmitted = true;
    errorOrDestroy(stream, er);
  } else {
    // the caller expect this to happen before if
    // it is async
    cb(er);
    stream._writableState.errorEmitted = true;
    errorOrDestroy(stream, er);
    // this can emit finish, but finish must
    // always follow error
    finishMaybe(stream, state);
  }
}
function onwriteStateUpdate(state) {
  state.writing = false;
  state.writecb = null;
  state.length -= state.writelen;
  state.writelen = 0;
}
function onwrite(stream, er) {
  var state = stream._writableState;
  var sync = state.sync;
  var cb = state.writecb;
  if (typeof cb !== 'function') throw new ERR_MULTIPLE_CALLBACK();
  onwriteStateUpdate(state);
  if (er) onwriteError(stream, state, sync, er, cb);else {
    // Check if we're actually ready to finish, but don't emit yet
    var finished = needFinish(state) || stream.destroyed;
    if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) {
      clearBuffer(stream, state);
    }
    if (sync) {
      process.nextTick(afterWrite, stream, state, finished, cb);
    } else {
      afterWrite(stream, state, finished, cb);
    }
  }
}
function afterWrite(stream, state, finished, cb) {
  if (!finished) onwriteDrain(stream, state);
  state.pendingcb--;
  cb();
  finishMaybe(stream, state);
}

// Must force callback to be called on nextTick, so that we don't
// emit 'drain' before the write() consumer gets the 'false' return
// value, and has a chance to attach a 'drain' listener.
function onwriteDrain(stream, state) {
  if (state.length === 0 && state.needDrain) {
    state.needDrain = false;
    stream.emit('drain');
  }
}

// if there's something in the buffer waiting, then process it
function clearBuffer(stream, state) {
  state.bufferProcessing = true;
  var entry = state.bufferedRequest;
  if (stream._writev && entry && entry.next) {
    // Fast case, write everything using _writev()
    var l = state.bufferedRequestCount;
    var buffer = new Array(l);
    var holder = state.corkedRequestsFree;
    holder.entry = entry;
    var count = 0;
    var allBuffers = true;
    while (entry) {
      buffer[count] = entry;
      if (!entry.isBuf) allBuffers = false;
      entry = entry.next;
      count += 1;
    }
    buffer.allBuffers = allBuffers;
    doWrite(stream, state, true, state.length, buffer, '', holder.finish);

    // doWrite is almost always async, defer these to save a bit of time
    // as the hot path ends with doWrite
    state.pendingcb++;
    state.lastBufferedRequest = null;
    if (holder.next) {
      state.corkedRequestsFree = holder.next;
      holder.next = null;
    } else {
      state.corkedRequestsFree = new CorkedRequest(state);
    }
    state.bufferedRequestCount = 0;
  } else {
    // Slow case, write chunks one-by-one
    while (entry) {
      var chunk = entry.chunk;
      var encoding = entry.encoding;
      var cb = entry.callback;
      var len = state.objectMode ? 1 : chunk.length;
      doWrite(stream, state, false, len, chunk, encoding, cb);
      entry = entry.next;
      state.bufferedRequestCount--;
      // if we didn't call the onwrite immediately, then
      // it means that we need to wait until it does.
      // also, that means that the chunk and cb are currently
      // being processed, so move the buffer counter past them.
      if (state.writing) {
        break;
      }
    }
    if (entry === null) state.lastBufferedRequest = null;
  }
  state.bufferedRequest = entry;
  state.bufferProcessing = false;
}
Writable.prototype._write = function (chunk, encoding, cb) {
  cb(new ERR_METHOD_NOT_IMPLEMENTED('_write()'));
};
Writable.prototype._writev = null;
Writable.prototype.end = function (chunk, encoding, cb) {
  var state = this._writableState;
  if (typeof chunk === 'function') {
    cb = chunk;
    chunk = null;
    encoding = null;
  } else if (typeof encoding === 'function') {
    cb = encoding;
    encoding = null;
  }
  if (chunk !== null && chunk !== undefined) this.write(chunk, encoding);

  // .end() fully uncorks
  if (state.corked) {
    state.corked = 1;
    this.uncork();
  }

  // ignore unnecessary end() calls.
  if (!state.ending) endWritable(this, state, cb);
  return this;
};
Object.defineProperty(Writable.prototype, 'writableLength', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState.length;
  }
});
function needFinish(state) {
  return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing;
}
function callFinal(stream, state) {
  stream._final(function (err) {
    state.pendingcb--;
    if (err) {
      errorOrDestroy(stream, err);
    }
    state.prefinished = true;
    stream.emit('prefinish');
    finishMaybe(stream, state);
  });
}
function prefinish(stream, state) {
  if (!state.prefinished && !state.finalCalled) {
    if (typeof stream._final === 'function' && !state.destroyed) {
      state.pendingcb++;
      state.finalCalled = true;
      process.nextTick(callFinal, stream, state);
    } else {
      state.prefinished = true;
      stream.emit('prefinish');
    }
  }
}
function finishMaybe(stream, state) {
  var need = needFinish(state);
  if (need) {
    prefinish(stream, state);
    if (state.pendingcb === 0) {
      state.finished = true;
      stream.emit('finish');
      if (state.autoDestroy) {
        // In case of duplex streams we need a way to detect
        // if the readable side is ready for autoDestroy as well
        var rState = stream._readableState;
        if (!rState || rState.autoDestroy && rState.endEmitted) {
          stream.destroy();
        }
      }
    }
  }
  return need;
}
function endWritable(stream, state, cb) {
  state.ending = true;
  finishMaybe(stream, state);
  if (cb) {
    if (state.finished) process.nextTick(cb);else stream.once('finish', cb);
  }
  state.ended = true;
  stream.writable = false;
}
function onCorkedFinish(corkReq, state, err) {
  var entry = corkReq.entry;
  corkReq.entry = null;
  while (entry) {
    var cb = entry.callback;
    state.pendingcb--;
    cb(err);
    entry = entry.next;
  }

  // reuse the free corkReq.
  state.corkedRequestsFree.next = corkReq;
}
Object.defineProperty(Writable.prototype, 'destroyed', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    if (this._writableState === undefined) {
      return false;
    }
    return this._writableState.destroyed;
  },
  set: function set(value) {
    // we ignore the value if the stream
    // has not been initialized yet
    if (!this._writableState) {
      return;
    }

    // backward compatibility, the user is explicitly
    // managing destroyed
    this._writableState.destroyed = value;
  }
});
Writable.prototype.destroy = destroyImpl.destroy;
Writable.prototype._undestroy = destroyImpl.undestroy;
Writable.prototype._destroy = function (err, cb) {
  cb(err);
};
}).call(this)}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{"../errors":13,"./_stream_duplex":14,"./internal/streams/destroy":21,"./internal/streams/state":25,"./internal/streams/stream":26,"_process":56,"buffer":51,"inherits":10,"util-deprecate":43}],19:[function(require,module,exports){
(function (process){(function (){
'use strict';

var _Object$setPrototypeO;
function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
var finished = require('./end-of-stream');
var kLastResolve = Symbol('lastResolve');
var kLastReject = Symbol('lastReject');
var kError = Symbol('error');
var kEnded = Symbol('ended');
var kLastPromise = Symbol('lastPromise');
var kHandlePromise = Symbol('handlePromise');
var kStream = Symbol('stream');
function createIterResult(value, done) {
  return {
    value: value,
    done: done
  };
}
function readAndResolve(iter) {
  var resolve = iter[kLastResolve];
  if (resolve !== null) {
    var data = iter[kStream].read();
    // we defer if data is null
    // we can be expecting either 'end' or
    // 'error'
    if (data !== null) {
      iter[kLastPromise] = null;
      iter[kLastResolve] = null;
      iter[kLastReject] = null;
      resolve(createIterResult(data, false));
    }
  }
}
function onReadable(iter) {
  // we wait for the next tick, because it might
  // emit an error with process.nextTick
  process.nextTick(readAndResolve, iter);
}
function wrapForNext(lastPromise, iter) {
  return function (resolve, reject) {
    lastPromise.then(function () {
      if (iter[kEnded]) {
        resolve(createIterResult(undefined, true));
        return;
      }
      iter[kHandlePromise](resolve, reject);
    }, reject);
  };
}
var AsyncIteratorPrototype = Object.getPrototypeOf(function () {});
var ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf((_Object$setPrototypeO = {
  get stream() {
    return this[kStream];
  },
  next: function next() {
    var _this = this;
    // if we have detected an error in the meanwhile
    // reject straight away
    var error = this[kError];
    if (error !== null) {
      return Promise.reject(error);
    }
    if (this[kEnded]) {
      return Promise.resolve(createIterResult(undefined, true));
    }
    if (this[kStream].destroyed) {
      // We need to defer via nextTick because if .destroy(err) is
      // called, the error will be emitted via nextTick, and
      // we cannot guarantee that there is no error lingering around
      // waiting to be emitted.
      return new Promise(function (resolve, reject) {
        process.nextTick(function () {
          if (_this[kError]) {
            reject(_this[kError]);
          } else {
            resolve(createIterResult(undefined, true));
          }
        });
      });
    }

    // if we have multiple next() calls
    // we will wait for the previous Promise to finish
    // this logic is optimized to support for await loops,
    // where next() is only called once at a time
    var lastPromise = this[kLastPromise];
    var promise;
    if (lastPromise) {
      promise = new Promise(wrapForNext(lastPromise, this));
    } else {
      // fast path needed to support multiple this.push()
      // without triggering the next() queue
      var data = this[kStream].read();
      if (data !== null) {
        return Promise.resolve(createIterResult(data, false));
      }
      promise = new Promise(this[kHandlePromise]);
    }
    this[kLastPromise] = promise;
    return promise;
  }
}, _defineProperty(_Object$setPrototypeO, Symbol.asyncIterator, function () {
  return this;
}), _defineProperty(_Object$setPrototypeO, "return", function _return() {
  var _this2 = this;
  // destroy(err, cb) is a private API
  // we can guarantee we have that here, because we control the
  // Readable class this is attached to
  return new Promise(function (resolve, reject) {
    _this2[kStream].destroy(null, function (err) {
      if (err) {
        reject(err);
        return;
      }
      resolve(createIterResult(undefined, true));
    });
  });
}), _Object$setPrototypeO), AsyncIteratorPrototype);
var createReadableStreamAsyncIterator = function createReadableStreamAsyncIterator(stream) {
  var _Object$create;
  var iterator = Object.create(ReadableStreamAsyncIteratorPrototype, (_Object$create = {}, _defineProperty(_Object$create, kStream, {
    value: stream,
    writable: true
  }), _defineProperty(_Object$create, kLastResolve, {
    value: null,
    writable: true
  }), _defineProperty(_Object$create, kLastReject, {
    value: null,
    writable: true
  }), _defineProperty(_Object$create, kError, {
    value: null,
    writable: true
  }), _defineProperty(_Object$create, kEnded, {
    value: stream._readableState.endEmitted,
    writable: true
  }), _defineProperty(_Object$create, kHandlePromise, {
    value: function value(resolve, reject) {
      var data = iterator[kStream].read();
      if (data) {
        iterator[kLastPromise] = null;
        iterator[kLastResolve] = null;
        iterator[kLastReject] = null;
        resolve(createIterResult(data, false));
      } else {
        iterator[kLastResolve] = resolve;
        iterator[kLastReject] = reject;
      }
    },
    writable: true
  }), _Object$create));
  iterator[kLastPromise] = null;
  finished(stream, function (err) {
    if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
      var reject = iterator[kLastReject];
      // reject if we are waiting for data in the Promise
      // returned by next() and store the error
      if (reject !== null) {
        iterator[kLastPromise] = null;
        iterator[kLastResolve] = null;
        iterator[kLastReject] = null;
        reject(err);
      }
      iterator[kError] = err;
      return;
    }
    var resolve = iterator[kLastResolve];
    if (resolve !== null) {
      iterator[kLastPromise] = null;
      iterator[kLastResolve] = null;
      iterator[kLastReject] = null;
      resolve(createIterResult(undefined, true));
    }
    iterator[kEnded] = true;
  });
  stream.on('readable', onReadable.bind(null, iterator));
  return iterator;
};
module.exports = createReadableStreamAsyncIterator;
}).call(this)}).call(this,require('_process'))
},{"./end-of-stream":22,"_process":56}],20:[function(require,module,exports){
'use strict';

function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }
function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }
function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, _toPropertyKey(descriptor.key), descriptor); } }
function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
var _require = require('buffer'),
  Buffer = _require.Buffer;
var _require2 = require('util'),
  inspect = _require2.inspect;
var custom = inspect && inspect.custom || 'inspect';
function copyBuffer(src, target, offset) {
  Buffer.prototype.copy.call(src, target, offset);
}
module.exports = /*#__PURE__*/function () {
  function BufferList() {
    _classCallCheck(this, BufferList);
    this.head = null;
    this.tail = null;
    this.length = 0;
  }
  _createClass(BufferList, [{
    key: "push",
    value: function push(v) {
      var entry = {
        data: v,
        next: null
      };
      if (this.length > 0) this.tail.next = entry;else this.head = entry;
      this.tail = entry;
      ++this.length;
    }
  }, {
    key: "unshift",
    value: function unshift(v) {
      var entry = {
        data: v,
        next: this.head
      };
      if (this.length === 0) this.tail = entry;
      this.head = entry;
      ++this.length;
    }
  }, {
    key: "shift",
    value: function shift() {
      if (this.length === 0) return;
      var ret = this.head.data;
      if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
      --this.length;
      return ret;
    }
  }, {
    key: "clear",
    value: function clear() {
      this.head = this.tail = null;
      this.length = 0;
    }
  }, {
    key: "join",
    value: function join(s) {
      if (this.length === 0) return '';
      var p = this.head;
      var ret = '' + p.data;
      while (p = p.next) ret += s + p.data;
      return ret;
    }
  }, {
    key: "concat",
    value: function concat(n) {
      if (this.length === 0) return Buffer.alloc(0);
      var ret = Buffer.allocUnsafe(n >>> 0);
      var p = this.head;
      var i = 0;
      while (p) {
        copyBuffer(p.data, ret, i);
        i += p.data.length;
        p = p.next;
      }
      return ret;
    }

    // Consumes a specified amount of bytes or characters from the buffered data.
  }, {
    key: "consume",
    value: function consume(n, hasStrings) {
      var ret;
      if (n < this.head.data.length) {
        // `slice` is the same for buffers and strings.
        ret = this.head.data.slice(0, n);
        this.head.data = this.head.data.slice(n);
      } else if (n === this.head.data.length) {
        // First chunk is a perfect match.
        ret = this.shift();
      } else {
        // Result spans more than one buffer.
        ret = hasStrings ? this._getString(n) : this._getBuffer(n);
      }
      return ret;
    }
  }, {
    key: "first",
    value: function first() {
      return this.head.data;
    }

    // Consumes a specified amount of characters from the buffered data.
  }, {
    key: "_getString",
    value: function _getString(n) {
      var p = this.head;
      var c = 1;
      var ret = p.data;
      n -= ret.length;
      while (p = p.next) {
        var str = p.data;
        var nb = n > str.length ? str.length : n;
        if (nb === str.length) ret += str;else ret += str.slice(0, n);
        n -= nb;
        if (n === 0) {
          if (nb === str.length) {
            ++c;
            if (p.next) this.head = p.next;else this.head = this.tail = null;
          } else {
            this.head = p;
            p.data = str.slice(nb);
          }
          break;
        }
        ++c;
      }
      this.length -= c;
      return ret;
    }

    // Consumes a specified amount of bytes from the buffered data.
  }, {
    key: "_getBuffer",
    value: function _getBuffer(n) {
      var ret = Buffer.allocUnsafe(n);
      var p = this.head;
      var c = 1;
      p.data.copy(ret);
      n -= p.data.length;
      while (p = p.next) {
        var buf = p.data;
        var nb = n > buf.length ? buf.length : n;
        buf.copy(ret, ret.length - n, 0, nb);
        n -= nb;
        if (n === 0) {
          if (nb === buf.length) {
            ++c;
            if (p.next) this.head = p.next;else this.head = this.tail = null;
          } else {
            this.head = p;
            p.data = buf.slice(nb);
          }
          break;
        }
        ++c;
      }
      this.length -= c;
      return ret;
    }

    // Make sure the linked list only shows the minimal necessary information.
  }, {
    key: custom,
    value: function value(_, options) {
      return inspect(this, _objectSpread(_objectSpread({}, options), {}, {
        // Only inspect one level.
        depth: 0,
        // It should not recurse.
        customInspect: false
      }));
    }
  }]);
  return BufferList;
}();
},{"buffer":51,"util":50}],21:[function(require,module,exports){
(function (process){(function (){
'use strict';

// undocumented cb() API, needed for core, not for public API
function destroy(err, cb) {
  var _this = this;
  var readableDestroyed = this._readableState && this._readableState.destroyed;
  var writableDestroyed = this._writableState && this._writableState.destroyed;
  if (readableDestroyed || writableDestroyed) {
    if (cb) {
      cb(err);
    } else if (err) {
      if (!this._writableState) {
        process.nextTick(emitErrorNT, this, err);
      } else if (!this._writableState.errorEmitted) {
        this._writableState.errorEmitted = true;
        process.nextTick(emitErrorNT, this, err);
      }
    }
    return this;
  }

  // we set destroyed to true before firing error callbacks in order
  // to make it re-entrance safe in case destroy() is called within callbacks

  if (this._readableState) {
    this._readableState.destroyed = true;
  }

  // if this is a duplex stream mark the writable part as destroyed as well
  if (this._writableState) {
    this._writableState.destroyed = true;
  }
  this._destroy(err || null, function (err) {
    if (!cb && err) {
      if (!_this._writableState) {
        process.nextTick(emitErrorAndCloseNT, _this, err);
      } else if (!_this._writableState.errorEmitted) {
        _this._writableState.errorEmitted = true;
        process.nextTick(emitErrorAndCloseNT, _this, err);
      } else {
        process.nextTick(emitCloseNT, _this);
      }
    } else if (cb) {
      process.nextTick(emitCloseNT, _this);
      cb(err);
    } else {
      process.nextTick(emitCloseNT, _this);
    }
  });
  return this;
}
function emitErrorAndCloseNT(self, err) {
  emitErrorNT(self, err);
  emitCloseNT(self);
}
function emitCloseNT(self) {
  if (self._writableState && !self._writableState.emitClose) return;
  if (self._readableState && !self._readableState.emitClose) return;
  self.emit('close');
}
function undestroy() {
  if (this._readableState) {
    this._readableState.destroyed = false;
    this._readableState.reading = false;
    this._readableState.ended = false;
    this._readableState.endEmitted = false;
  }
  if (this._writableState) {
    this._writableState.destroyed = false;
    this._writableState.ended = false;
    this._writableState.ending = false;
    this._writableState.finalCalled = false;
    this._writableState.prefinished = false;
    this._writableState.finished = false;
    this._writableState.errorEmitted = false;
  }
}
function emitErrorNT(self, err) {
  self.emit('error', err);
}
function errorOrDestroy(stream, err) {
  // We have tests that rely on errors being emitted
  // in the same tick, so changing this is semver major.
  // For now when you opt-in to autoDestroy we allow
  // the error to be emitted nextTick. In a future
  // semver major update we should change the default to this.

  var rState = stream._readableState;
  var wState = stream._writableState;
  if (rState && rState.autoDestroy || wState && wState.autoDestroy) stream.destroy(err);else stream.emit('error', err);
}
module.exports = {
  destroy: destroy,
  undestroy: undestroy,
  errorOrDestroy: errorOrDestroy
};
}).call(this)}).call(this,require('_process'))
},{"_process":56}],22:[function(require,module,exports){
// Ported from https://github.com/mafintosh/end-of-stream with
// permission from the author, Mathias Buus (@mafintosh).

'use strict';

var ERR_STREAM_PREMATURE_CLOSE = require('../../../errors').codes.ERR_STREAM_PREMATURE_CLOSE;
function once(callback) {
  var called = false;
  return function () {
    if (called) return;
    called = true;
    for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
      args[_key] = arguments[_key];
    }
    callback.apply(this, args);
  };
}
function noop() {}
function isRequest(stream) {
  return stream.setHeader && typeof stream.abort === 'function';
}
function eos(stream, opts, callback) {
  if (typeof opts === 'function') return eos(stream, null, opts);
  if (!opts) opts = {};
  callback = once(callback || noop);
  var readable = opts.readable || opts.readable !== false && stream.readable;
  var writable = opts.writable || opts.writable !== false && stream.writable;
  var onlegacyfinish = function onlegacyfinish() {
    if (!stream.writable) onfinish();
  };
  var writableEnded = stream._writableState && stream._writableState.finished;
  var onfinish = function onfinish() {
    writable = false;
    writableEnded = true;
    if (!readable) callback.call(stream);
  };
  var readableEnded = stream._readableState && stream._readableState.endEmitted;
  var onend = function onend() {
    readable = false;
    readableEnded = true;
    if (!writable) callback.call(stream);
  };
  var onerror = function onerror(err) {
    callback.call(stream, err);
  };
  var onclose = function onclose() {
    var err;
    if (readable && !readableEnded) {
      if (!stream._readableState || !stream._readableState.ended) err = new ERR_STREAM_PREMATURE_CLOSE();
      return callback.call(stream, err);
    }
    if (writable && !writableEnded) {
      if (!stream._writableState || !stream._writableState.ended) err = new ERR_STREAM_PREMATURE_CLOSE();
      return callback.call(stream, err);
    }
  };
  var onrequest = function onrequest() {
    stream.req.on('finish', onfinish);
  };
  if (isRequest(stream)) {
    stream.on('complete', onfinish);
    stream.on('abort', onclose);
    if (stream.req) onrequest();else stream.on('request', onrequest);
  } else if (writable && !stream._writableState) {
    // legacy streams
    stream.on('end', onlegacyfinish);
    stream.on('close', onlegacyfinish);
  }
  stream.on('end', onend);
  stream.on('finish', onfinish);
  if (opts.error !== false) stream.on('error', onerror);
  stream.on('close', onclose);
  return function () {
    stream.removeListener('complete', onfinish);
    stream.removeListener('abort', onclose);
    stream.removeListener('request', onrequest);
    if (stream.req) stream.req.removeListener('finish', onfinish);
    stream.removeListener('end', onlegacyfinish);
    stream.removeListener('close', onlegacyfinish);
    stream.removeListener('finish', onfinish);
    stream.removeListener('end', onend);
    stream.removeListener('error', onerror);
    stream.removeListener('close', onclose);
  };
}
module.exports = eos;
},{"../../../errors":13}],23:[function(require,module,exports){
module.exports = function () {
  throw new Error('Readable.from is not available in the browser')
};

},{}],24:[function(require,module,exports){
// Ported from https://github.com/mafintosh/pump with
// permission from the author, Mathias Buus (@mafintosh).

'use strict';

var eos;
function once(callback) {
  var called = false;
  return function () {
    if (called) return;
    called = true;
    callback.apply(void 0, arguments);
  };
}
var _require$codes = require('../../../errors').codes,
  ERR_MISSING_ARGS = _require$codes.ERR_MISSING_ARGS,
  ERR_STREAM_DESTROYED = _require$codes.ERR_STREAM_DESTROYED;
function noop(err) {
  // Rethrow the error if it exists to avoid swallowing it
  if (err) throw err;
}
function isRequest(stream) {
  return stream.setHeader && typeof stream.abort === 'function';
}
function destroyer(stream, reading, writing, callback) {
  callback = once(callback);
  var closed = false;
  stream.on('close', function () {
    closed = true;
  });
  if (eos === undefined) eos = require('./end-of-stream');
  eos(stream, {
    readable: reading,
    writable: writing
  }, function (err) {
    if (err) return callback(err);
    closed = true;
    callback();
  });
  var destroyed = false;
  return function (err) {
    if (closed) return;
    if (destroyed) return;
    destroyed = true;

    // request.destroy just do .end - .abort is what we want
    if (isRequest(stream)) return stream.abort();
    if (typeof stream.destroy === 'function') return stream.destroy();
    callback(err || new ERR_STREAM_DESTROYED('pipe'));
  };
}
function call(fn) {
  fn();
}
function pipe(from, to) {
  return from.pipe(to);
}
function popCallback(streams) {
  if (!streams.length) return noop;
  if (typeof streams[streams.length - 1] !== 'function') return noop;
  return streams.pop();
}
function pipeline() {
  for (var _len = arguments.length, streams = new Array(_len), _key = 0; _key < _len; _key++) {
    streams[_key] = arguments[_key];
  }
  var callback = popCallback(streams);
  if (Array.isArray(streams[0])) streams = streams[0];
  if (streams.length < 2) {
    throw new ERR_MISSING_ARGS('streams');
  }
  var error;
  var destroys = streams.map(function (stream, i) {
    var reading = i < streams.length - 1;
    var writing = i > 0;
    return destroyer(stream, reading, writing, function (err) {
      if (!error) error = err;
      if (err) destroys.forEach(call);
      if (reading) return;
      destroys.forEach(call);
      callback(error);
    });
  });
  return streams.reduce(pipe);
}
module.exports = pipeline;
},{"../../../errors":13,"./end-of-stream":22}],25:[function(require,module,exports){
'use strict';

var ERR_INVALID_OPT_VALUE = require('../../../errors').codes.ERR_INVALID_OPT_VALUE;
function highWaterMarkFrom(options, isDuplex, duplexKey) {
  return options.highWaterMark != null ? options.highWaterMark : isDuplex ? options[duplexKey] : null;
}
function getHighWaterMark(state, options, duplexKey, isDuplex) {
  var hwm = highWaterMarkFrom(options, isDuplex, duplexKey);
  if (hwm != null) {
    if (!(isFinite(hwm) && Math.floor(hwm) === hwm) || hwm < 0) {
      var name = isDuplex ? duplexKey : 'highWaterMark';
      throw new ERR_INVALID_OPT_VALUE(name, hwm);
    }
    return Math.floor(hwm);
  }

  // Default value
  return state.objectMode ? 16 : 16 * 1024;
}
module.exports = {
  getHighWaterMark: getHighWaterMark
};
},{"../../../errors":13}],26:[function(require,module,exports){
module.exports = require('events').EventEmitter;

},{"events":52}],27:[function(require,module,exports){
exports = module.exports = require('./lib/_stream_readable.js');
exports.Stream = exports;
exports.Readable = exports;
exports.Writable = require('./lib/_stream_writable.js');
exports.Duplex = require('./lib/_stream_duplex.js');
exports.Transform = require('./lib/_stream_transform.js');
exports.PassThrough = require('./lib/_stream_passthrough.js');
exports.finished = require('./lib/internal/streams/end-of-stream.js');
exports.pipeline = require('./lib/internal/streams/pipeline.js');

},{"./lib/_stream_duplex.js":14,"./lib/_stream_passthrough.js":15,"./lib/_stream_readable.js":16,"./lib/_stream_transform.js":17,"./lib/_stream_writable.js":18,"./lib/internal/streams/end-of-stream.js":22,"./lib/internal/streams/pipeline.js":24}],28:[function(require,module,exports){
'use strict'
var Buffer = require('buffer').Buffer
var inherits = require('inherits')
var HashBase = require('hash-base')

var ARRAY16 = new Array(16)

var zl = [
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
  7, 4, 13, 1, 10, 6, 15, 3, 12, 0, 9, 5, 2, 14, 11, 8,
  3, 10, 14, 4, 9, 15, 8, 1, 2, 7, 0, 6, 13, 11, 5, 12,
  1, 9, 11, 10, 0, 8, 12, 4, 13, 3, 7, 15, 14, 5, 6, 2,
  4, 0, 5, 9, 7, 12, 2, 10, 14, 1, 3, 8, 11, 6, 15, 13
]

var zr = [
  5, 14, 7, 0, 9, 2, 11, 4, 13, 6, 15, 8, 1, 10, 3, 12,
  6, 11, 3, 7, 0, 13, 5, 10, 14, 15, 8, 12, 4, 9, 1, 2,
  15, 5, 1, 3, 7, 14, 6, 9, 11, 8, 12, 2, 10, 0, 4, 13,
  8, 6, 4, 1, 3, 11, 15, 0, 5, 12, 2, 13, 9, 7, 10, 14,
  12, 15, 10, 4, 1, 5, 8, 7, 6, 2, 13, 14, 0, 3, 9, 11
]

var sl = [
  11, 14, 15, 12, 5, 8, 7, 9, 11, 13, 14, 15, 6, 7, 9, 8,
  7, 6, 8, 13, 11, 9, 7, 15, 7, 12, 15, 9, 11, 7, 13, 12,
  11, 13, 6, 7, 14, 9, 13, 15, 14, 8, 13, 6, 5, 12, 7, 5,
  11, 12, 14, 15, 14, 15, 9, 8, 9, 14, 5, 6, 8, 6, 5, 12,
  9, 15, 5, 11, 6, 8, 13, 12, 5, 12, 13, 14, 11, 8, 5, 6
]

var sr = [
  8, 9, 9, 11, 13, 15, 15, 5, 7, 7, 8, 11, 14, 14, 12, 6,
  9, 13, 15, 7, 12, 8, 9, 11, 7, 7, 12, 7, 6, 15, 13, 11,
  9, 7, 15, 11, 8, 6, 6, 14, 12, 13, 5, 14, 13, 13, 7, 5,
  15, 5, 8, 11, 14, 14, 6, 14, 6, 9, 12, 9, 12, 5, 15, 8,
  8, 5, 12, 9, 12, 5, 14, 6, 8, 13, 6, 5, 15, 13, 11, 11
]

var hl = [0x00000000, 0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xa953fd4e]
var hr = [0x50a28be6, 0x5c4dd124, 0x6d703ef3, 0x7a6d76e9, 0x00000000]

function RIPEMD160 () {
  HashBase.call(this, 64)

  // state
  this._a = 0x67452301
  this._b = 0xefcdab89
  this._c = 0x98badcfe
  this._d = 0x10325476
  this._e = 0xc3d2e1f0
}

inherits(RIPEMD160, HashBase)

RIPEMD160.prototype._update = function () {
  var words = ARRAY16
  for (var j = 0; j < 16; ++j) words[j] = this._block.readInt32LE(j * 4)

  var al = this._a | 0
  var bl = this._b | 0
  var cl = this._c | 0
  var dl = this._d | 0
  var el = this._e | 0

  var ar = this._a | 0
  var br = this._b | 0
  var cr = this._c | 0
  var dr = this._d | 0
  var er = this._e | 0

  // computation
  for (var i = 0; i < 80; i += 1) {
    var tl
    var tr
    if (i < 16) {
      tl = fn1(al, bl, cl, dl, el, words[zl[i]], hl[0], sl[i])
      tr = fn5(ar, br, cr, dr, er, words[zr[i]], hr[0], sr[i])
    } else if (i < 32) {
      tl = fn2(al, bl, cl, dl, el, words[zl[i]], hl[1], sl[i])
      tr = fn4(ar, br, cr, dr, er, words[zr[i]], hr[1], sr[i])
    } else if (i < 48) {
      tl = fn3(al, bl, cl, dl, el, words[zl[i]], hl[2], sl[i])
      tr = fn3(ar, br, cr, dr, er, words[zr[i]], hr[2], sr[i])
    } else if (i < 64) {
      tl = fn4(al, bl, cl, dl, el, words[zl[i]], hl[3], sl[i])
      tr = fn2(ar, br, cr, dr, er, words[zr[i]], hr[3], sr[i])
    } else { // if (i<80) {
      tl = fn5(al, bl, cl, dl, el, words[zl[i]], hl[4], sl[i])
      tr = fn1(ar, br, cr, dr, er, words[zr[i]], hr[4], sr[i])
    }

    al = el
    el = dl
    dl = rotl(cl, 10)
    cl = bl
    bl = tl

    ar = er
    er = dr
    dr = rotl(cr, 10)
    cr = br
    br = tr
  }

  // update state
  var t = (this._b + cl + dr) | 0
  this._b = (this._c + dl + er) | 0
  this._c = (this._d + el + ar) | 0
  this._d = (this._e + al + br) | 0
  this._e = (this._a + bl + cr) | 0
  this._a = t
}

RIPEMD160.prototype._digest = function () {
  // create padding and handle blocks
  this._block[this._blockOffset++] = 0x80
  if (this._blockOffset > 56) {
    this._block.fill(0, this._blockOffset, 64)
    this._update()
    this._blockOffset = 0
  }

  this._block.fill(0, this._blockOffset, 56)
  this._block.writeUInt32LE(this._length[0], 56)
  this._block.writeUInt32LE(this._length[1], 60)
  this._update()

  // produce result
  var buffer = Buffer.alloc ? Buffer.alloc(20) : new Buffer(20)
  buffer.writeInt32LE(this._a, 0)
  buffer.writeInt32LE(this._b, 4)
  buffer.writeInt32LE(this._c, 8)
  buffer.writeInt32LE(this._d, 12)
  buffer.writeInt32LE(this._e, 16)
  return buffer
}

function rotl (x, n) {
  return (x << n) | (x >>> (32 - n))
}

function fn1 (a, b, c, d, e, m, k, s) {
  return (rotl((a + (b ^ c ^ d) + m + k) | 0, s) + e) | 0
}

function fn2 (a, b, c, d, e, m, k, s) {
  return (rotl((a + ((b & c) | ((~b) & d)) + m + k) | 0, s) + e) | 0
}

function fn3 (a, b, c, d, e, m, k, s) {
  return (rotl((a + ((b | (~c)) ^ d) + m + k) | 0, s) + e) | 0
}

function fn4 (a, b, c, d, e, m, k, s) {
  return (rotl((a + ((b & d) | (c & (~d))) + m + k) | 0, s) + e) | 0
}

function fn5 (a, b, c, d, e, m, k, s) {
  return (rotl((a + (b ^ (c | (~d))) + m + k) | 0, s) + e) | 0
}

module.exports = RIPEMD160

},{"buffer":51,"hash-base":9,"inherits":10}],29:[function(require,module,exports){
/*! safe-buffer. MIT License. Feross Aboukhadijeh <https://feross.org/opensource> */
/* eslint-disable node/no-deprecated-api */
var buffer = require('buffer')
var Buffer = buffer.Buffer

// alternative to using Object.keys for old browsers
function copyProps (src, dst) {
  for (var key in src) {
    dst[key] = src[key]
  }
}
if (Buffer.from && Buffer.alloc && Buffer.allocUnsafe && Buffer.allocUnsafeSlow) {
  module.exports = buffer
} else {
  // Copy properties from require('buffer')
  copyProps(buffer, exports)
  exports.Buffer = SafeBuffer
}

function SafeBuffer (arg, encodingOrOffset, length) {
  return Buffer(arg, encodingOrOffset, length)
}

SafeBuffer.prototype = Object.create(Buffer.prototype)

// Copy static methods from Buffer
copyProps(Buffer, SafeBuffer)

SafeBuffer.from = function (arg, encodingOrOffset, length) {
  if (typeof arg === 'number') {
    throw new TypeError('Argument must not be a number')
  }
  return Buffer(arg, encodingOrOffset, length)
}

SafeBuffer.alloc = function (size, fill, encoding) {
  if (typeof size !== 'number') {
    throw new TypeError('Argument must be a number')
  }
  var buf = Buffer(size)
  if (fill !== undefined) {
    if (typeof encoding === 'string') {
      buf.fill(fill, encoding)
    } else {
      buf.fill(fill)
    }
  } else {
    buf.fill(0)
  }
  return buf
}

SafeBuffer.allocUnsafe = function (size) {
  if (typeof size !== 'number') {
    throw new TypeError('Argument must be a number')
  }
  return Buffer(size)
}

SafeBuffer.allocUnsafeSlow = function (size) {
  if (typeof size !== 'number') {
    throw new TypeError('Argument must be a number')
  }
  return buffer.SlowBuffer(size)
}

},{"buffer":51}],30:[function(require,module,exports){
var Buffer = require('safe-buffer').Buffer

// prototype class for hash functions
function Hash (blockSize, finalSize) {
  this._block = Buffer.alloc(blockSize)
  this._finalSize = finalSize
  this._blockSize = blockSize
  this._len = 0
}

Hash.prototype.update = function (data, enc) {
  if (typeof data === 'string') {
    enc = enc || 'utf8'
    data = Buffer.from(data, enc)
  }

  var block = this._block
  var blockSize = this._blockSize
  var length = data.length
  var accum = this._len

  for (var offset = 0; offset < length;) {
    var assigned = accum % blockSize
    var remainder = Math.min(length - offset, blockSize - assigned)

    for (var i = 0; i < remainder; i++) {
      block[assigned + i] = data[offset + i]
    }

    accum += remainder
    offset += remainder

    if ((accum % blockSize) === 0) {
      this._update(block)
    }
  }

  this._len += length
  return this
}

Hash.prototype.digest = function (enc) {
  var rem = this._len % this._blockSize

  this._block[rem] = 0x80

  // zero (rem + 1) trailing bits, where (rem + 1) is the smallest
  // non-negative solution to the equation (length + 1 + (rem + 1)) === finalSize mod blockSize
  this._block.fill(0, rem + 1)

  if (rem >= this._finalSize) {
    this._update(this._block)
    this._block.fill(0)
  }

  var bits = this._len * 8

  // uint32
  if (bits <= 0xffffffff) {
    this._block.writeUInt32BE(bits, this._blockSize - 4)

  // uint64
  } else {
    var lowBits = (bits & 0xffffffff) >>> 0
    var highBits = (bits - lowBits) / 0x100000000

    this._block.writeUInt32BE(highBits, this._blockSize - 8)
    this._block.writeUInt32BE(lowBits, this._blockSize - 4)
  }

  this._update(this._block)
  var hash = this._hash()

  return enc ? hash.toString(enc) : hash
}

Hash.prototype._update = function () {
  throw new Error('_update must be implemented by subclass')
}

module.exports = Hash

},{"safe-buffer":29}],31:[function(require,module,exports){
var exports = module.exports = function SHA (algorithm) {
  algorithm = algorithm.toLowerCase()

  var Algorithm = exports[algorithm]
  if (!Algorithm) throw new Error(algorithm + ' is not supported (we accept pull requests)')

  return new Algorithm()
}

exports.sha = require('./sha')
exports.sha1 = require('./sha1')
exports.sha224 = require('./sha224')
exports.sha256 = require('./sha256')
exports.sha384 = require('./sha384')
exports.sha512 = require('./sha512')

},{"./sha":32,"./sha1":33,"./sha224":34,"./sha256":35,"./sha384":36,"./sha512":37}],32:[function(require,module,exports){
/*
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-0, as defined
 * in FIPS PUB 180-1
 * This source code is derived from sha1.js of the same repository.
 * The difference between SHA-0 and SHA-1 is just a bitwise rotate left
 * operation was added.
 */

var inherits = require('inherits')
var Hash = require('./hash')
var Buffer = require('safe-buffer').Buffer

var K = [
  0x5a827999, 0x6ed9eba1, 0x8f1bbcdc | 0, 0xca62c1d6 | 0
]

var W = new Array(80)

function Sha () {
  this.init()
  this._w = W

  Hash.call(this, 64, 56)
}

inherits(Sha, Hash)

Sha.prototype.init = function () {
  this._a = 0x67452301
  this._b = 0xefcdab89
  this._c = 0x98badcfe
  this._d = 0x10325476
  this._e = 0xc3d2e1f0

  return this
}

function rotl5 (num) {
  return (num << 5) | (num >>> 27)
}

function rotl30 (num) {
  return (num << 30) | (num >>> 2)
}

function ft (s, b, c, d) {
  if (s === 0) return (b & c) | ((~b) & d)
  if (s === 2) return (b & c) | (b & d) | (c & d)
  return b ^ c ^ d
}

Sha.prototype._update = function (M) {
  var W = this._w

  var a = this._a | 0
  var b = this._b | 0
  var c = this._c | 0
  var d = this._d | 0
  var e = this._e | 0

  for (var i = 0; i < 16; ++i) W[i] = M.readInt32BE(i * 4)
  for (; i < 80; ++i) W[i] = W[i - 3] ^ W[i - 8] ^ W[i - 14] ^ W[i - 16]

  for (var j = 0; j < 80; ++j) {
    var s = ~~(j / 20)
    var t = (rotl5(a) + ft(s, b, c, d) + e + W[j] + K[s]) | 0

    e = d
    d = c
    c = rotl30(b)
    b = a
    a = t
  }

  this._a = (a + this._a) | 0
  this._b = (b + this._b) | 0
  this._c = (c + this._c) | 0
  this._d = (d + this._d) | 0
  this._e = (e + this._e) | 0
}

Sha.prototype._hash = function () {
  var H = Buffer.allocUnsafe(20)

  H.writeInt32BE(this._a | 0, 0)
  H.writeInt32BE(this._b | 0, 4)
  H.writeInt32BE(this._c | 0, 8)
  H.writeInt32BE(this._d | 0, 12)
  H.writeInt32BE(this._e | 0, 16)

  return H
}

module.exports = Sha

},{"./hash":30,"inherits":10,"safe-buffer":29}],33:[function(require,module,exports){
/*
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
 * in FIPS PUB 180-1
 * Version 2.1a Copyright Paul Johnston 2000 - 2002.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for details.
 */

var inherits = require('inherits')
var Hash = require('./hash')
var Buffer = require('safe-buffer').Buffer

var K = [
  0x5a827999, 0x6ed9eba1, 0x8f1bbcdc | 0, 0xca62c1d6 | 0
]

var W = new Array(80)

function Sha1 () {
  this.init()
  this._w = W

  Hash.call(this, 64, 56)
}

inherits(Sha1, Hash)

Sha1.prototype.init = function () {
  this._a = 0x67452301
  this._b = 0xefcdab89
  this._c = 0x98badcfe
  this._d = 0x10325476
  this._e = 0xc3d2e1f0

  return this
}

function rotl1 (num) {
  return (num << 1) | (num >>> 31)
}

function rotl5 (num) {
  return (num << 5) | (num >>> 27)
}

function rotl30 (num) {
  return (num << 30) | (num >>> 2)
}

function ft (s, b, c, d) {
  if (s === 0) return (b & c) | ((~b) & d)
  if (s === 2) return (b & c) | (b & d) | (c & d)
  return b ^ c ^ d
}

Sha1.prototype._update = function (M) {
  var W = this._w

  var a = this._a | 0
  var b = this._b | 0
  var c = this._c | 0
  var d = this._d | 0
  var e = this._e | 0

  for (var i = 0; i < 16; ++i) W[i] = M.readInt32BE(i * 4)
  for (; i < 80; ++i) W[i] = rotl1(W[i - 3] ^ W[i - 8] ^ W[i - 14] ^ W[i - 16])

  for (var j = 0; j < 80; ++j) {
    var s = ~~(j / 20)
    var t = (rotl5(a) + ft(s, b, c, d) + e + W[j] + K[s]) | 0

    e = d
    d = c
    c = rotl30(b)
    b = a
    a = t
  }

  this._a = (a + this._a) | 0
  this._b = (b + this._b) | 0
  this._c = (c + this._c) | 0
  this._d = (d + this._d) | 0
  this._e = (e + this._e) | 0
}

Sha1.prototype._hash = function () {
  var H = Buffer.allocUnsafe(20)

  H.writeInt32BE(this._a | 0, 0)
  H.writeInt32BE(this._b | 0, 4)
  H.writeInt32BE(this._c | 0, 8)
  H.writeInt32BE(this._d | 0, 12)
  H.writeInt32BE(this._e | 0, 16)

  return H
}

module.exports = Sha1

},{"./hash":30,"inherits":10,"safe-buffer":29}],34:[function(require,module,exports){
/**
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-256, as defined
 * in FIPS 180-2
 * Version 2.2-beta Copyright Angel Marin, Paul Johnston 2000 - 2009.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 *
 */

var inherits = require('inherits')
var Sha256 = require('./sha256')
var Hash = require('./hash')
var Buffer = require('safe-buffer').Buffer

var W = new Array(64)

function Sha224 () {
  this.init()

  this._w = W // new Array(64)

  Hash.call(this, 64, 56)
}

inherits(Sha224, Sha256)

Sha224.prototype.init = function () {
  this._a = 0xc1059ed8
  this._b = 0x367cd507
  this._c = 0x3070dd17
  this._d = 0xf70e5939
  this._e = 0xffc00b31
  this._f = 0x68581511
  this._g = 0x64f98fa7
  this._h = 0xbefa4fa4

  return this
}

Sha224.prototype._hash = function () {
  var H = Buffer.allocUnsafe(28)

  H.writeInt32BE(this._a, 0)
  H.writeInt32BE(this._b, 4)
  H.writeInt32BE(this._c, 8)
  H.writeInt32BE(this._d, 12)
  H.writeInt32BE(this._e, 16)
  H.writeInt32BE(this._f, 20)
  H.writeInt32BE(this._g, 24)

  return H
}

module.exports = Sha224

},{"./hash":30,"./sha256":35,"inherits":10,"safe-buffer":29}],35:[function(require,module,exports){
/**
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-256, as defined
 * in FIPS 180-2
 * Version 2.2-beta Copyright Angel Marin, Paul Johnston 2000 - 2009.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 *
 */

var inherits = require('inherits')
var Hash = require('./hash')
var Buffer = require('safe-buffer').Buffer

var K = [
  0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5,
  0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5,
  0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3,
  0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174,
  0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC,
  0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA,
  0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7,
  0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967,
  0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13,
  0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85,
  0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3,
  0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070,
  0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5,
  0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3,
  0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208,
  0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2
]

var W = new Array(64)

function Sha256 () {
  this.init()

  this._w = W // new Array(64)

  Hash.call(this, 64, 56)
}

inherits(Sha256, Hash)

Sha256.prototype.init = function () {
  this._a = 0x6a09e667
  this._b = 0xbb67ae85
  this._c = 0x3c6ef372
  this._d = 0xa54ff53a
  this._e = 0x510e527f
  this._f = 0x9b05688c
  this._g = 0x1f83d9ab
  this._h = 0x5be0cd19

  return this
}

function ch (x, y, z) {
  return z ^ (x & (y ^ z))
}

function maj (x, y, z) {
  return (x & y) | (z & (x | y))
}

function sigma0 (x) {
  return (x >>> 2 | x << 30) ^ (x >>> 13 | x << 19) ^ (x >>> 22 | x << 10)
}

function sigma1 (x) {
  return (x >>> 6 | x << 26) ^ (x >>> 11 | x << 21) ^ (x >>> 25 | x << 7)
}

function gamma0 (x) {
  return (x >>> 7 | x << 25) ^ (x >>> 18 | x << 14) ^ (x >>> 3)
}

function gamma1 (x) {
  return (x >>> 17 | x << 15) ^ (x >>> 19 | x << 13) ^ (x >>> 10)
}

Sha256.prototype._update = function (M) {
  var W = this._w

  var a = this._a | 0
  var b = this._b | 0
  var c = this._c | 0
  var d = this._d | 0
  var e = this._e | 0
  var f = this._f | 0
  var g = this._g | 0
  var h = this._h | 0

  for (var i = 0; i < 16; ++i) W[i] = M.readInt32BE(i * 4)
  for (; i < 64; ++i) W[i] = (gamma1(W[i - 2]) + W[i - 7] + gamma0(W[i - 15]) + W[i - 16]) | 0

  for (var j = 0; j < 64; ++j) {
    var T1 = (h + sigma1(e) + ch(e, f, g) + K[j] + W[j]) | 0
    var T2 = (sigma0(a) + maj(a, b, c)) | 0

    h = g
    g = f
    f = e
    e = (d + T1) | 0
    d = c
    c = b
    b = a
    a = (T1 + T2) | 0
  }

  this._a = (a + this._a) | 0
  this._b = (b + this._b) | 0
  this._c = (c + this._c) | 0
  this._d = (d + this._d) | 0
  this._e = (e + this._e) | 0
  this._f = (f + this._f) | 0
  this._g = (g + this._g) | 0
  this._h = (h + this._h) | 0
}

Sha256.prototype._hash = function () {
  var H = Buffer.allocUnsafe(32)

  H.writeInt32BE(this._a, 0)
  H.writeInt32BE(this._b, 4)
  H.writeInt32BE(this._c, 8)
  H.writeInt32BE(this._d, 12)
  H.writeInt32BE(this._e, 16)
  H.writeInt32BE(this._f, 20)
  H.writeInt32BE(this._g, 24)
  H.writeInt32BE(this._h, 28)

  return H
}

module.exports = Sha256

},{"./hash":30,"inherits":10,"safe-buffer":29}],36:[function(require,module,exports){
var inherits = require('inherits')
var SHA512 = require('./sha512')
var Hash = require('./hash')
var Buffer = require('safe-buffer').Buffer

var W = new Array(160)

function Sha384 () {
  this.init()
  this._w = W

  Hash.call(this, 128, 112)
}

inherits(Sha384, SHA512)

Sha384.prototype.init = function () {
  this._ah = 0xcbbb9d5d
  this._bh = 0x629a292a
  this._ch = 0x9159015a
  this._dh = 0x152fecd8
  this._eh = 0x67332667
  this._fh = 0x8eb44a87
  this._gh = 0xdb0c2e0d
  this._hh = 0x47b5481d

  this._al = 0xc1059ed8
  this._bl = 0x367cd507
  this._cl = 0x3070dd17
  this._dl = 0xf70e5939
  this._el = 0xffc00b31
  this._fl = 0x68581511
  this._gl = 0x64f98fa7
  this._hl = 0xbefa4fa4

  return this
}

Sha384.prototype._hash = function () {
  var H = Buffer.allocUnsafe(48)

  function writeInt64BE (h, l, offset) {
    H.writeInt32BE(h, offset)
    H.writeInt32BE(l, offset + 4)
  }

  writeInt64BE(this._ah, this._al, 0)
  writeInt64BE(this._bh, this._bl, 8)
  writeInt64BE(this._ch, this._cl, 16)
  writeInt64BE(this._dh, this._dl, 24)
  writeInt64BE(this._eh, this._el, 32)
  writeInt64BE(this._fh, this._fl, 40)

  return H
}

module.exports = Sha384

},{"./hash":30,"./sha512":37,"inherits":10,"safe-buffer":29}],37:[function(require,module,exports){
var inherits = require('inherits')
var Hash = require('./hash')
var Buffer = require('safe-buffer').Buffer

var K = [
  0x428a2f98, 0xd728ae22, 0x71374491, 0x23ef65cd,
  0xb5c0fbcf, 0xec4d3b2f, 0xe9b5dba5, 0x8189dbbc,
  0x3956c25b, 0xf348b538, 0x59f111f1, 0xb605d019,
  0x923f82a4, 0xaf194f9b, 0xab1c5ed5, 0xda6d8118,
  0xd807aa98, 0xa3030242, 0x12835b01, 0x45706fbe,
  0x243185be, 0x4ee4b28c, 0x550c7dc3, 0xd5ffb4e2,
  0x72be5d74, 0xf27b896f, 0x80deb1fe, 0x3b1696b1,
  0x9bdc06a7, 0x25c71235, 0xc19bf174, 0xcf692694,
  0xe49b69c1, 0x9ef14ad2, 0xefbe4786, 0x384f25e3,
  0x0fc19dc6, 0x8b8cd5b5, 0x240ca1cc, 0x77ac9c65,
  0x2de92c6f, 0x592b0275, 0x4a7484aa, 0x6ea6e483,
  0x5cb0a9dc, 0xbd41fbd4, 0x76f988da, 0x831153b5,
  0x983e5152, 0xee66dfab, 0xa831c66d, 0x2db43210,
  0xb00327c8, 0x98fb213f, 0xbf597fc7, 0xbeef0ee4,
  0xc6e00bf3, 0x3da88fc2, 0xd5a79147, 0x930aa725,
  0x06ca6351, 0xe003826f, 0x14292967, 0x0a0e6e70,
  0x27b70a85, 0x46d22ffc, 0x2e1b2138, 0x5c26c926,
  0x4d2c6dfc, 0x5ac42aed, 0x53380d13, 0x9d95b3df,
  0x650a7354, 0x8baf63de, 0x766a0abb, 0x3c77b2a8,
  0x81c2c92e, 0x47edaee6, 0x92722c85, 0x1482353b,
  0xa2bfe8a1, 0x4cf10364, 0xa81a664b, 0xbc423001,
  0xc24b8b70, 0xd0f89791, 0xc76c51a3, 0x0654be30,
  0xd192e819, 0xd6ef5218, 0xd6990624, 0x5565a910,
  0xf40e3585, 0x5771202a, 0x106aa070, 0x32bbd1b8,
  0x19a4c116, 0xb8d2d0c8, 0x1e376c08, 0x5141ab53,
  0x2748774c, 0xdf8eeb99, 0x34b0bcb5, 0xe19b48a8,
  0x391c0cb3, 0xc5c95a63, 0x4ed8aa4a, 0xe3418acb,
  0x5b9cca4f, 0x7763e373, 0x682e6ff3, 0xd6b2b8a3,
  0x748f82ee, 0x5defb2fc, 0x78a5636f, 0x43172f60,
  0x84c87814, 0xa1f0ab72, 0x8cc70208, 0x1a6439ec,
  0x90befffa, 0x23631e28, 0xa4506ceb, 0xde82bde9,
  0xbef9a3f7, 0xb2c67915, 0xc67178f2, 0xe372532b,
  0xca273ece, 0xea26619c, 0xd186b8c7, 0x21c0c207,
  0xeada7dd6, 0xcde0eb1e, 0xf57d4f7f, 0xee6ed178,
  0x06f067aa, 0x72176fba, 0x0a637dc5, 0xa2c898a6,
  0x113f9804, 0xbef90dae, 0x1b710b35, 0x131c471b,
  0x28db77f5, 0x23047d84, 0x32caab7b, 0x40c72493,
  0x3c9ebe0a, 0x15c9bebc, 0x431d67c4, 0x9c100d4c,
  0x4cc5d4be, 0xcb3e42b6, 0x597f299c, 0xfc657e2a,
  0x5fcb6fab, 0x3ad6faec, 0x6c44198c, 0x4a475817
]

var W = new Array(160)

function Sha512 () {
  this.init()
  this._w = W

  Hash.call(this, 128, 112)
}

inherits(Sha512, Hash)

Sha512.prototype.init = function () {
  this._ah = 0x6a09e667
  this._bh = 0xbb67ae85
  this._ch = 0x3c6ef372
  this._dh = 0xa54ff53a
  this._eh = 0x510e527f
  this._fh = 0x9b05688c
  this._gh = 0x1f83d9ab
  this._hh = 0x5be0cd19

  this._al = 0xf3bcc908
  this._bl = 0x84caa73b
  this._cl = 0xfe94f82b
  this._dl = 0x5f1d36f1
  this._el = 0xade682d1
  this._fl = 0x2b3e6c1f
  this._gl = 0xfb41bd6b
  this._hl = 0x137e2179

  return this
}

function Ch (x, y, z) {
  return z ^ (x & (y ^ z))
}

function maj (x, y, z) {
  return (x & y) | (z & (x | y))
}

function sigma0 (x, xl) {
  return (x >>> 28 | xl << 4) ^ (xl >>> 2 | x << 30) ^ (xl >>> 7 | x << 25)
}

function sigma1 (x, xl) {
  return (x >>> 14 | xl << 18) ^ (x >>> 18 | xl << 14) ^ (xl >>> 9 | x << 23)
}

function Gamma0 (x, xl) {
  return (x >>> 1 | xl << 31) ^ (x >>> 8 | xl << 24) ^ (x >>> 7)
}

function Gamma0l (x, xl) {
  return (x >>> 1 | xl << 31) ^ (x >>> 8 | xl << 24) ^ (x >>> 7 | xl << 25)
}

function Gamma1 (x, xl) {
  return (x >>> 19 | xl << 13) ^ (xl >>> 29 | x << 3) ^ (x >>> 6)
}

function Gamma1l (x, xl) {
  return (x >>> 19 | xl << 13) ^ (xl >>> 29 | x << 3) ^ (x >>> 6 | xl << 26)
}

function getCarry (a, b) {
  return (a >>> 0) < (b >>> 0) ? 1 : 0
}

Sha512.prototype._update = function (M) {
  var W = this._w

  var ah = this._ah | 0
  var bh = this._bh | 0
  var ch = this._ch | 0
  var dh = this._dh | 0
  var eh = this._eh | 0
  var fh = this._fh | 0
  var gh = this._gh | 0
  var hh = this._hh | 0

  var al = this._al | 0
  var bl = this._bl | 0
  var cl = this._cl | 0
  var dl = this._dl | 0
  var el = this._el | 0
  var fl = this._fl | 0
  var gl = this._gl | 0
  var hl = this._hl | 0

  for (var i = 0; i < 32; i += 2) {
    W[i] = M.readInt32BE(i * 4)
    W[i + 1] = M.readInt32BE(i * 4 + 4)
  }
  for (; i < 160; i += 2) {
    var xh = W[i - 15 * 2]
    var xl = W[i - 15 * 2 + 1]
    var gamma0 = Gamma0(xh, xl)
    var gamma0l = Gamma0l(xl, xh)

    xh = W[i - 2 * 2]
    xl = W[i - 2 * 2 + 1]
    var gamma1 = Gamma1(xh, xl)
    var gamma1l = Gamma1l(xl, xh)

    // W[i] = gamma0 + W[i - 7] + gamma1 + W[i - 16]
    var Wi7h = W[i - 7 * 2]
    var Wi7l = W[i - 7 * 2 + 1]

    var Wi16h = W[i - 16 * 2]
    var Wi16l = W[i - 16 * 2 + 1]

    var Wil = (gamma0l + Wi7l) | 0
    var Wih = (gamma0 + Wi7h + getCarry(Wil, gamma0l)) | 0
    Wil = (Wil + gamma1l) | 0
    Wih = (Wih + gamma1 + getCarry(Wil, gamma1l)) | 0
    Wil = (Wil + Wi16l) | 0
    Wih = (Wih + Wi16h + getCarry(Wil, Wi16l)) | 0

    W[i] = Wih
    W[i + 1] = Wil
  }

  for (var j = 0; j < 160; j += 2) {
    Wih = W[j]
    Wil = W[j + 1]

    var majh = maj(ah, bh, ch)
    var majl = maj(al, bl, cl)

    var sigma0h = sigma0(ah, al)
    var sigma0l = sigma0(al, ah)
    var sigma1h = sigma1(eh, el)
    var sigma1l = sigma1(el, eh)

    // t1 = h + sigma1 + ch + K[j] + W[j]
    var Kih = K[j]
    var Kil = K[j + 1]

    var chh = Ch(eh, fh, gh)
    var chl = Ch(el, fl, gl)

    var t1l = (hl + sigma1l) | 0
    var t1h = (hh + sigma1h + getCarry(t1l, hl)) | 0
    t1l = (t1l + chl) | 0
    t1h = (t1h + chh + getCarry(t1l, chl)) | 0
    t1l = (t1l + Kil) | 0
    t1h = (t1h + Kih + getCarry(t1l, Kil)) | 0
    t1l = (t1l + Wil) | 0
    t1h = (t1h + Wih + getCarry(t1l, Wil)) | 0

    // t2 = sigma0 + maj
    var t2l = (sigma0l + majl) | 0
    var t2h = (sigma0h + majh + getCarry(t2l, sigma0l)) | 0

    hh = gh
    hl = gl
    gh = fh
    gl = fl
    fh = eh
    fl = el
    el = (dl + t1l) | 0
    eh = (dh + t1h + getCarry(el, dl)) | 0
    dh = ch
    dl = cl
    ch = bh
    cl = bl
    bh = ah
    bl = al
    al = (t1l + t2l) | 0
    ah = (t1h + t2h + getCarry(al, t1l)) | 0
  }

  this._al = (this._al + al) | 0
  this._bl = (this._bl + bl) | 0
  this._cl = (this._cl + cl) | 0
  this._dl = (this._dl + dl) | 0
  this._el = (this._el + el) | 0
  this._fl = (this._fl + fl) | 0
  this._gl = (this._gl + gl) | 0
  this._hl = (this._hl + hl) | 0

  this._ah = (this._ah + ah + getCarry(this._al, al)) | 0
  this._bh = (this._bh + bh + getCarry(this._bl, bl)) | 0
  this._ch = (this._ch + ch + getCarry(this._cl, cl)) | 0
  this._dh = (this._dh + dh + getCarry(this._dl, dl)) | 0
  this._eh = (this._eh + eh + getCarry(this._el, el)) | 0
  this._fh = (this._fh + fh + getCarry(this._fl, fl)) | 0
  this._gh = (this._gh + gh + getCarry(this._gl, gl)) | 0
  this._hh = (this._hh + hh + getCarry(this._hl, hl)) | 0
}

Sha512.prototype._hash = function () {
  var H = Buffer.allocUnsafe(64)

  function writeInt64BE (h, l, offset) {
    H.writeInt32BE(h, offset)
    H.writeInt32BE(l, offset + 4)
  }

  writeInt64BE(this._ah, this._al, 0)
  writeInt64BE(this._bh, this._bl, 8)
  writeInt64BE(this._ch, this._cl, 16)
  writeInt64BE(this._dh, this._dl, 24)
  writeInt64BE(this._eh, this._el, 32)
  writeInt64BE(this._fh, this._fl, 40)
  writeInt64BE(this._gh, this._gl, 48)
  writeInt64BE(this._hh, this._hl, 56)

  return H
}

module.exports = Sha512

},{"./hash":30,"inherits":10,"safe-buffer":29}],38:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

/*<replacement>*/

var Buffer = require('safe-buffer').Buffer;
/*</replacement>*/

var isEncoding = Buffer.isEncoding || function (encoding) {
  encoding = '' + encoding;
  switch (encoding && encoding.toLowerCase()) {
    case 'hex':case 'utf8':case 'utf-8':case 'ascii':case 'binary':case 'base64':case 'ucs2':case 'ucs-2':case 'utf16le':case 'utf-16le':case 'raw':
      return true;
    default:
      return false;
  }
};

function _normalizeEncoding(enc) {
  if (!enc) return 'utf8';
  var retried;
  while (true) {
    switch (enc) {
      case 'utf8':
      case 'utf-8':
        return 'utf8';
      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return 'utf16le';
      case 'latin1':
      case 'binary':
        return 'latin1';
      case 'base64':
      case 'ascii':
      case 'hex':
        return enc;
      default:
        if (retried) return; // undefined
        enc = ('' + enc).toLowerCase();
        retried = true;
    }
  }
};

// Do not cache `Buffer.isEncoding` when checking encoding names as some
// modules monkey-patch it to support additional encodings
function normalizeEncoding(enc) {
  var nenc = _normalizeEncoding(enc);
  if (typeof nenc !== 'string' && (Buffer.isEncoding === isEncoding || !isEncoding(enc))) throw new Error('Unknown encoding: ' + enc);
  return nenc || enc;
}

// StringDecoder provides an interface for efficiently splitting a series of
// buffers into a series of JS strings without breaking apart multi-byte
// characters.
exports.StringDecoder = StringDecoder;
function StringDecoder(encoding) {
  this.encoding = normalizeEncoding(encoding);
  var nb;
  switch (this.encoding) {
    case 'utf16le':
      this.text = utf16Text;
      this.end = utf16End;
      nb = 4;
      break;
    case 'utf8':
      this.fillLast = utf8FillLast;
      nb = 4;
      break;
    case 'base64':
      this.text = base64Text;
      this.end = base64End;
      nb = 3;
      break;
    default:
      this.write = simpleWrite;
      this.end = simpleEnd;
      return;
  }
  this.lastNeed = 0;
  this.lastTotal = 0;
  this.lastChar = Buffer.allocUnsafe(nb);
}

StringDecoder.prototype.write = function (buf) {
  if (buf.length === 0) return '';
  var r;
  var i;
  if (this.lastNeed) {
    r = this.fillLast(buf);
    if (r === undefined) return '';
    i = this.lastNeed;
    this.lastNeed = 0;
  } else {
    i = 0;
  }
  if (i < buf.length) return r ? r + this.text(buf, i) : this.text(buf, i);
  return r || '';
};

StringDecoder.prototype.end = utf8End;

// Returns only complete characters in a Buffer
StringDecoder.prototype.text = utf8Text;

// Attempts to complete a partial non-UTF-8 character using bytes from a Buffer
StringDecoder.prototype.fillLast = function (buf) {
  if (this.lastNeed <= buf.length) {
    buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, this.lastNeed);
    return this.lastChar.toString(this.encoding, 0, this.lastTotal);
  }
  buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, buf.length);
  this.lastNeed -= buf.length;
};

// Checks the type of a UTF-8 byte, whether it's ASCII, a leading byte, or a
// continuation byte. If an invalid byte is detected, -2 is returned.
function utf8CheckByte(byte) {
  if (byte <= 0x7F) return 0;else if (byte >> 5 === 0x06) return 2;else if (byte >> 4 === 0x0E) return 3;else if (byte >> 3 === 0x1E) return 4;
  return byte >> 6 === 0x02 ? -1 : -2;
}

// Checks at most 3 bytes at the end of a Buffer in order to detect an
// incomplete multi-byte UTF-8 character. The total number of bytes (2, 3, or 4)
// needed to complete the UTF-8 character (if applicable) are returned.
function utf8CheckIncomplete(self, buf, i) {
  var j = buf.length - 1;
  if (j < i) return 0;
  var nb = utf8CheckByte(buf[j]);
  if (nb >= 0) {
    if (nb > 0) self.lastNeed = nb - 1;
    return nb;
  }
  if (--j < i || nb === -2) return 0;
  nb = utf8CheckByte(buf[j]);
  if (nb >= 0) {
    if (nb > 0) self.lastNeed = nb - 2;
    return nb;
  }
  if (--j < i || nb === -2) return 0;
  nb = utf8CheckByte(buf[j]);
  if (nb >= 0) {
    if (nb > 0) {
      if (nb === 2) nb = 0;else self.lastNeed = nb - 3;
    }
    return nb;
  }
  return 0;
}

// Validates as many continuation bytes for a multi-byte UTF-8 character as
// needed or are available. If we see a non-continuation byte where we expect
// one, we "replace" the validated continuation bytes we've seen so far with
// a single UTF-8 replacement character ('\ufffd'), to match v8's UTF-8 decoding
// behavior. The continuation byte check is included three times in the case
// where all of the continuation bytes for a character exist in the same buffer.
// It is also done this way as a slight performance increase instead of using a
// loop.
function utf8CheckExtraBytes(self, buf, p) {
  if ((buf[0] & 0xC0) !== 0x80) {
    self.lastNeed = 0;
    return '\ufffd';
  }
  if (self.lastNeed > 1 && buf.length > 1) {
    if ((buf[1] & 0xC0) !== 0x80) {
      self.lastNeed = 1;
      return '\ufffd';
    }
    if (self.lastNeed > 2 && buf.length > 2) {
      if ((buf[2] & 0xC0) !== 0x80) {
        self.lastNeed = 2;
        return '\ufffd';
      }
    }
  }
}

// Attempts to complete a multi-byte UTF-8 character using bytes from a Buffer.
function utf8FillLast(buf) {
  var p = this.lastTotal - this.lastNeed;
  var r = utf8CheckExtraBytes(this, buf, p);
  if (r !== undefined) return r;
  if (this.lastNeed <= buf.length) {
    buf.copy(this.lastChar, p, 0, this.lastNeed);
    return this.lastChar.toString(this.encoding, 0, this.lastTotal);
  }
  buf.copy(this.lastChar, p, 0, buf.length);
  this.lastNeed -= buf.length;
}

// Returns all complete UTF-8 characters in a Buffer. If the Buffer ended on a
// partial character, the character's bytes are buffered until the required
// number of bytes are available.
function utf8Text(buf, i) {
  var total = utf8CheckIncomplete(this, buf, i);
  if (!this.lastNeed) return buf.toString('utf8', i);
  this.lastTotal = total;
  var end = buf.length - (total - this.lastNeed);
  buf.copy(this.lastChar, 0, end);
  return buf.toString('utf8', i, end);
}

// For UTF-8, a replacement character is added when ending on a partial
// character.
function utf8End(buf) {
  var r = buf && buf.length ? this.write(buf) : '';
  if (this.lastNeed) return r + '\ufffd';
  return r;
}

// UTF-16LE typically needs two bytes per character, but even if we have an even
// number of bytes available, we need to check if we end on a leading/high
// surrogate. In that case, we need to wait for the next two bytes in order to
// decode the last character properly.
function utf16Text(buf, i) {
  if ((buf.length - i) % 2 === 0) {
    var r = buf.toString('utf16le', i);
    if (r) {
      var c = r.charCodeAt(r.length - 1);
      if (c >= 0xD800 && c <= 0xDBFF) {
        this.lastNeed = 2;
        this.lastTotal = 4;
        this.lastChar[0] = buf[buf.length - 2];
        this.lastChar[1] = buf[buf.length - 1];
        return r.slice(0, -1);
      }
    }
    return r;
  }
  this.lastNeed = 1;
  this.lastTotal = 2;
  this.lastChar[0] = buf[buf.length - 1];
  return buf.toString('utf16le', i, buf.length - 1);
}

// For UTF-16LE we do not explicitly append special replacement characters if we
// end on a partial character, we simply let v8 handle that.
function utf16End(buf) {
  var r = buf && buf.length ? this.write(buf) : '';
  if (this.lastNeed) {
    var end = this.lastTotal - this.lastNeed;
    return r + this.lastChar.toString('utf16le', 0, end);
  }
  return r;
}

function base64Text(buf, i) {
  var n = (buf.length - i) % 3;
  if (n === 0) return buf.toString('base64', i);
  this.lastNeed = 3 - n;
  this.lastTotal = 3;
  if (n === 1) {
    this.lastChar[0] = buf[buf.length - 1];
  } else {
    this.lastChar[0] = buf[buf.length - 2];
    this.lastChar[1] = buf[buf.length - 1];
  }
  return buf.toString('base64', i, buf.length - n);
}

function base64End(buf) {
  var r = buf && buf.length ? this.write(buf) : '';
  if (this.lastNeed) return r + this.lastChar.toString('base64', 0, 3 - this.lastNeed);
  return r;
}

// Pass bytes on through for single-byte encodings (e.g. ascii, latin1, hex)
function simpleWrite(buf) {
  return buf.toString(this.encoding);
}

function simpleEnd(buf) {
  return buf && buf.length ? this.write(buf) : '';
}
},{"safe-buffer":29}],39:[function(require,module,exports){
var native = require('./native')

function getTypeName (fn) {
  return fn.name || fn.toString().match(/function (.*?)\s*\(/)[1]
}

function getValueTypeName (value) {
  return native.Nil(value) ? '' : getTypeName(value.constructor)
}

function getValue (value) {
  if (native.Function(value)) return ''
  if (native.String(value)) return JSON.stringify(value)
  if (value && native.Object(value)) return ''
  return value
}

function captureStackTrace (e, t) {
  if (Error.captureStackTrace) {
    Error.captureStackTrace(e, t)
  }
}

function tfJSON (type) {
  if (native.Function(type)) return type.toJSON ? type.toJSON() : getTypeName(type)
  if (native.Array(type)) return 'Array'
  if (type && native.Object(type)) return 'Object'

  return type !== undefined ? type : ''
}

function tfErrorString (type, value, valueTypeName) {
  var valueJson = getValue(value)

  return 'Expected ' + tfJSON(type) + ', got' +
    (valueTypeName !== '' ? ' ' + valueTypeName : '') +
    (valueJson !== '' ? ' ' + valueJson : '')
}

function TfTypeError (type, value, valueTypeName) {
  valueTypeName = valueTypeName || getValueTypeName(value)
  this.message = tfErrorString(type, value, valueTypeName)

  captureStackTrace(this, TfTypeError)
  this.__type = type
  this.__value = value
  this.__valueTypeName = valueTypeName
}

TfTypeError.prototype = Object.create(Error.prototype)
TfTypeError.prototype.constructor = TfTypeError

function tfPropertyErrorString (type, label, name, value, valueTypeName) {
  var description = '" of type '
  if (label === 'key') description = '" with key type '

  return tfErrorString('property "' + tfJSON(name) + description + tfJSON(type), value, valueTypeName)
}

function TfPropertyTypeError (type, property, label, value, valueTypeName) {
  if (type) {
    valueTypeName = valueTypeName || getValueTypeName(value)
    this.message = tfPropertyErrorString(type, label, property, value, valueTypeName)
  } else {
    this.message = 'Unexpected property "' + property + '"'
  }

  captureStackTrace(this, TfTypeError)
  this.__label = label
  this.__property = property
  this.__type = type
  this.__value = value
  this.__valueTypeName = valueTypeName
}

TfPropertyTypeError.prototype = Object.create(Error.prototype)
TfPropertyTypeError.prototype.constructor = TfTypeError

function tfCustomError (expected, actual) {
  return new TfTypeError(expected, {}, actual)
}

function tfSubError (e, property, label) {
  // sub child?
  if (e instanceof TfPropertyTypeError) {
    property = property + '.' + e.__property

    e = new TfPropertyTypeError(
      e.__type, property, e.__label, e.__value, e.__valueTypeName
    )

  // child?
  } else if (e instanceof TfTypeError) {
    e = new TfPropertyTypeError(
      e.__type, property, label, e.__value, e.__valueTypeName
    )
  }

  captureStackTrace(e)
  return e
}

module.exports = {
  TfTypeError: TfTypeError,
  TfPropertyTypeError: TfPropertyTypeError,
  tfCustomError: tfCustomError,
  tfSubError: tfSubError,
  tfJSON: tfJSON,
  getValueTypeName: getValueTypeName
}

},{"./native":42}],40:[function(require,module,exports){
(function (Buffer){(function (){
var NATIVE = require('./native')
var ERRORS = require('./errors')

function _Buffer (value) {
  return Buffer.isBuffer(value)
}

function Hex (value) {
  return typeof value === 'string' && /^([0-9a-f]{2})+$/i.test(value)
}

function _LengthN (type, length) {
  var name = type.toJSON()

  function Length (value) {
    if (!type(value)) return false
    if (value.length === length) return true

    throw ERRORS.tfCustomError(name + '(Length: ' + length + ')', name + '(Length: ' + value.length + ')')
  }
  Length.toJSON = function () { return name }

  return Length
}

var _ArrayN = _LengthN.bind(null, NATIVE.Array)
var _BufferN = _LengthN.bind(null, _Buffer)
var _HexN = _LengthN.bind(null, Hex)
var _StringN = _LengthN.bind(null, NATIVE.String)

function Range (a, b, f) {
  f = f || NATIVE.Number
  function _range (value, strict) {
    return f(value, strict) && (value > a) && (value < b)
  }
  _range.toJSON = function () {
    return `${f.toJSON()} between [${a}, ${b}]`
  }
  return _range
}

var INT53_MAX = Math.pow(2, 53) - 1

function Finite (value) {
  return typeof value === 'number' && isFinite(value)
}
function Int8 (value) { return ((value << 24) >> 24) === value }
function Int16 (value) { return ((value << 16) >> 16) === value }
function Int32 (value) { return (value | 0) === value }
function Int53 (value) {
  return typeof value === 'number' &&
    value >= -INT53_MAX &&
    value <= INT53_MAX &&
    Math.floor(value) === value
}
function UInt8 (value) { return (value & 0xff) === value }
function UInt16 (value) { return (value & 0xffff) === value }
function UInt32 (value) { return (value >>> 0) === value }
function UInt53 (value) {
  return typeof value === 'number' &&
    value >= 0 &&
    value <= INT53_MAX &&
    Math.floor(value) === value
}

var types = {
  ArrayN: _ArrayN,
  Buffer: _Buffer,
  BufferN: _BufferN,
  Finite: Finite,
  Hex: Hex,
  HexN: _HexN,
  Int8: Int8,
  Int16: Int16,
  Int32: Int32,
  Int53: Int53,
  Range: Range,
  StringN: _StringN,
  UInt8: UInt8,
  UInt16: UInt16,
  UInt32: UInt32,
  UInt53: UInt53
}

for (var typeName in types) {
  types[typeName].toJSON = function (t) {
    return t
  }.bind(null, typeName)
}

module.exports = types

}).call(this)}).call(this,{"isBuffer":require("../../../../../../usr/local/lib/node_modules/browserify/node_modules/is-buffer/index.js")})
},{"../../../../../../usr/local/lib/node_modules/browserify/node_modules/is-buffer/index.js":55,"./errors":39,"./native":42}],41:[function(require,module,exports){
var ERRORS = require('./errors')
var NATIVE = require('./native')

// short-hand
var tfJSON = ERRORS.tfJSON
var TfTypeError = ERRORS.TfTypeError
var TfPropertyTypeError = ERRORS.TfPropertyTypeError
var tfSubError = ERRORS.tfSubError
var getValueTypeName = ERRORS.getValueTypeName

var TYPES = {
  arrayOf: function arrayOf (type, options) {
    type = compile(type)
    options = options || {}

    function _arrayOf (array, strict) {
      if (!NATIVE.Array(array)) return false
      if (NATIVE.Nil(array)) return false
      if (options.minLength !== undefined && array.length < options.minLength) return false
      if (options.maxLength !== undefined && array.length > options.maxLength) return false
      if (options.length !== undefined && array.length !== options.length) return false

      return array.every(function (value, i) {
        try {
          return typeforce(type, value, strict)
        } catch (e) {
          throw tfSubError(e, i)
        }
      })
    }
    _arrayOf.toJSON = function () {
      var str = '[' + tfJSON(type) + ']'
      if (options.length !== undefined) {
        str += '{' + options.length + '}'
      } else if (options.minLength !== undefined || options.maxLength !== undefined) {
        str += '{' +
          (options.minLength === undefined ? 0 : options.minLength) + ',' +
          (options.maxLength === undefined ? Infinity : options.maxLength) + '}'
      }
      return str
    }

    return _arrayOf
  },

  maybe: function maybe (type) {
    type = compile(type)

    function _maybe (value, strict) {
      return NATIVE.Nil(value) || type(value, strict, maybe)
    }
    _maybe.toJSON = function () { return '?' + tfJSON(type) }

    return _maybe
  },

  map: function map (propertyType, propertyKeyType) {
    propertyType = compile(propertyType)
    if (propertyKeyType) propertyKeyType = compile(propertyKeyType)

    function _map (value, strict) {
      if (!NATIVE.Object(value)) return false
      if (NATIVE.Nil(value)) return false

      for (var propertyName in value) {
        try {
          if (propertyKeyType) {
            typeforce(propertyKeyType, propertyName, strict)
          }
        } catch (e) {
          throw tfSubError(e, propertyName, 'key')
        }

        try {
          var propertyValue = value[propertyName]
          typeforce(propertyType, propertyValue, strict)
        } catch (e) {
          throw tfSubError(e, propertyName)
        }
      }

      return true
    }

    if (propertyKeyType) {
      _map.toJSON = function () {
        return '{' + tfJSON(propertyKeyType) + ': ' + tfJSON(propertyType) + '}'
      }
    } else {
      _map.toJSON = function () { return '{' + tfJSON(propertyType) + '}' }
    }

    return _map
  },

  object: function object (uncompiled) {
    var type = {}

    for (var typePropertyName in uncompiled) {
      type[typePropertyName] = compile(uncompiled[typePropertyName])
    }

    function _object (value, strict) {
      if (!NATIVE.Object(value)) return false
      if (NATIVE.Nil(value)) return false

      var propertyName

      try {
        for (propertyName in type) {
          var propertyType = type[propertyName]
          var propertyValue = value[propertyName]

          typeforce(propertyType, propertyValue, strict)
        }
      } catch (e) {
        throw tfSubError(e, propertyName)
      }

      if (strict) {
        for (propertyName in value) {
          if (type[propertyName]) continue

          throw new TfPropertyTypeError(undefined, propertyName)
        }
      }

      return true
    }
    _object.toJSON = function () { return tfJSON(type) }

    return _object
  },

  anyOf: function anyOf () {
    var types = [].slice.call(arguments).map(compile)

    function _anyOf (value, strict) {
      return types.some(function (type) {
        try {
          return typeforce(type, value, strict)
        } catch (e) {
          return false
        }
      })
    }
    _anyOf.toJSON = function () { return types.map(tfJSON).join('|') }

    return _anyOf
  },

  allOf: function allOf () {
    var types = [].slice.call(arguments).map(compile)

    function _allOf (value, strict) {
      return types.every(function (type) {
        try {
          return typeforce(type, value, strict)
        } catch (e) {
          return false
        }
      })
    }
    _allOf.toJSON = function () { return types.map(tfJSON).join(' & ') }

    return _allOf
  },

  quacksLike: function quacksLike (type) {
    function _quacksLike (value) {
      return type === getValueTypeName(value)
    }
    _quacksLike.toJSON = function () { return type }

    return _quacksLike
  },

  tuple: function tuple () {
    var types = [].slice.call(arguments).map(compile)

    function _tuple (values, strict) {
      if (NATIVE.Nil(values)) return false
      if (NATIVE.Nil(values.length)) return false
      if (strict && (values.length !== types.length)) return false

      return types.every(function (type, i) {
        try {
          return typeforce(type, values[i], strict)
        } catch (e) {
          throw tfSubError(e, i)
        }
      })
    }
    _tuple.toJSON = function () { return '(' + types.map(tfJSON).join(', ') + ')' }

    return _tuple
  },

  value: function value (expected) {
    function _value (actual) {
      return actual === expected
    }
    _value.toJSON = function () { return expected }

    return _value
  }
}

// TODO: deprecate
TYPES.oneOf = TYPES.anyOf

function compile (type) {
  if (NATIVE.String(type)) {
    if (type[0] === '?') return TYPES.maybe(type.slice(1))

    return NATIVE[type] || TYPES.quacksLike(type)
  } else if (type && NATIVE.Object(type)) {
    if (NATIVE.Array(type)) {
      if (type.length !== 1) throw new TypeError('Expected compile() parameter of type Array of length 1')
      return TYPES.arrayOf(type[0])
    }

    return TYPES.object(type)
  } else if (NATIVE.Function(type)) {
    return type
  }

  return TYPES.value(type)
}

function typeforce (type, value, strict, surrogate) {
  if (NATIVE.Function(type)) {
    if (type(value, strict)) return true

    throw new TfTypeError(surrogate || type, value)
  }

  // JIT
  return typeforce(compile(type), value, strict)
}

// assign types to typeforce function
for (var typeName in NATIVE) {
  typeforce[typeName] = NATIVE[typeName]
}

for (typeName in TYPES) {
  typeforce[typeName] = TYPES[typeName]
}

var EXTRA = require('./extra')
for (typeName in EXTRA) {
  typeforce[typeName] = EXTRA[typeName]
}

typeforce.compile = compile
typeforce.TfTypeError = TfTypeError
typeforce.TfPropertyTypeError = TfPropertyTypeError

module.exports = typeforce

},{"./errors":39,"./extra":40,"./native":42}],42:[function(require,module,exports){
var types = {
  Array: function (value) { return value !== null && value !== undefined && value.constructor === Array },
  Boolean: function (value) { return typeof value === 'boolean' },
  Function: function (value) { return typeof value === 'function' },
  Nil: function (value) { return value === undefined || value === null },
  Number: function (value) { return typeof value === 'number' },
  Object: function (value) { return typeof value === 'object' },
  String: function (value) { return typeof value === 'string' },
  '': function () { return true }
}

// TODO: deprecate
types.Null = types.Nil

for (var typeName in types) {
  types[typeName].toJSON = function (t) {
    return t
  }.bind(null, typeName)
}

module.exports = types

},{}],43:[function(require,module,exports){
(function (global){(function (){

/**
 * Module exports.
 */

module.exports = deprecate;

/**
 * Mark that a method should not be used.
 * Returns a modified function which warns once by default.
 *
 * If `localStorage.noDeprecation = true` is set, then it is a no-op.
 *
 * If `localStorage.throwDeprecation = true` is set, then deprecated functions
 * will throw an Error when invoked.
 *
 * If `localStorage.traceDeprecation = true` is set, then deprecated functions
 * will invoke `console.trace()` instead of `console.error()`.
 *
 * @param {Function} fn - the function to deprecate
 * @param {String} msg - the string to print to the console when `fn` is invoked
 * @returns {Function} a new "deprecated" version of `fn`
 * @api public
 */

function deprecate (fn, msg) {
  if (config('noDeprecation')) {
    return fn;
  }

  var warned = false;
  function deprecated() {
    if (!warned) {
      if (config('throwDeprecation')) {
        throw new Error(msg);
      } else if (config('traceDeprecation')) {
        console.trace(msg);
      } else {
        console.warn(msg);
      }
      warned = true;
    }
    return fn.apply(this, arguments);
  }

  return deprecated;
}

/**
 * Checks `localStorage` for boolean values for the given `name`.
 *
 * @param {String} name
 * @returns {Boolean}
 * @api private
 */

function config (name) {
  // accessing global.localStorage can trigger a DOMException in sandboxed iframes
  try {
    if (!global.localStorage) return false;
  } catch (_) {
    return false;
  }
  var val = global.localStorage[name];
  if (null == val) return false;
  return String(val).toLowerCase() === 'true';
}

}).call(this)}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
},{}],44:[function(require,module,exports){
(function (Buffer){(function (){
var bs58check = require('bs58check')

function decodeRaw (buffer, version) {
  // check version only if defined
  if (version !== undefined && buffer[0] !== version) throw new Error('Invalid network version')

  // uncompressed
  if (buffer.length === 33) {
    return {
      version: buffer[0],
      privateKey: buffer.slice(1, 33),
      compressed: false
    }
  }

  // invalid length
  if (buffer.length !== 34) throw new Error('Invalid WIF length')

  // invalid compression flag
  if (buffer[33] !== 0x01) throw new Error('Invalid compression flag')

  return {
    version: buffer[0],
    privateKey: buffer.slice(1, 33),
    compressed: true
  }
}

function encodeRaw (version, privateKey, compressed) {
  var result = new Buffer(compressed ? 34 : 33)

  result.writeUInt8(version, 0)
  privateKey.copy(result, 1)

  if (compressed) {
    result[33] = 0x01
  }

  return result
}

function decode (string, version) {
  return decodeRaw(bs58check.decode(string), version)
}

function encode (version, privateKey, compressed) {
  if (typeof version === 'number') return bs58check.encode(encodeRaw(version, privateKey, compressed))

  return bs58check.encode(
    encodeRaw(
      version.version,
      version.privateKey,
      version.compressed
    )
  )
}

module.exports = {
  decode: decode,
  decodeRaw: decodeRaw,
  encode: encode,
  encodeRaw: encodeRaw
}

}).call(this)}).call(this,require("buffer").Buffer)
},{"bs58check":48,"buffer":51}],45:[function(require,module,exports){
'use strict'
// base-x encoding / decoding
// Copyright (c) 2018 base-x contributors
// Copyright (c) 2014-2018 The Bitcoin Core developers (base58.cpp)
// Distributed under the MIT software license, see the accompanying
// file LICENSE or http://www.opensource.org/licenses/mit-license.php.
// @ts-ignore
var _Buffer = require('safe-buffer').Buffer
function base (ALPHABET) {
  if (ALPHABET.length >= 255) { throw new TypeError('Alphabet too long') }
  var BASE_MAP = new Uint8Array(256)
  for (var j = 0; j < BASE_MAP.length; j++) {
    BASE_MAP[j] = 255
  }
  for (var i = 0; i < ALPHABET.length; i++) {
    var x = ALPHABET.charAt(i)
    var xc = x.charCodeAt(0)
    if (BASE_MAP[xc] !== 255) { throw new TypeError(x + ' is ambiguous') }
    BASE_MAP[xc] = i
  }
  var BASE = ALPHABET.length
  var LEADER = ALPHABET.charAt(0)
  var FACTOR = Math.log(BASE) / Math.log(256) // log(BASE) / log(256), rounded up
  var iFACTOR = Math.log(256) / Math.log(BASE) // log(256) / log(BASE), rounded up
  function encode (source) {
    if (Array.isArray(source) || source instanceof Uint8Array) { source = _Buffer.from(source) }
    if (!_Buffer.isBuffer(source)) { throw new TypeError('Expected Buffer') }
    if (source.length === 0) { return '' }
        // Skip & count leading zeroes.
    var zeroes = 0
    var length = 0
    var pbegin = 0
    var pend = source.length
    while (pbegin !== pend && source[pbegin] === 0) {
      pbegin++
      zeroes++
    }
        // Allocate enough space in big-endian base58 representation.
    var size = ((pend - pbegin) * iFACTOR + 1) >>> 0
    var b58 = new Uint8Array(size)
        // Process the bytes.
    while (pbegin !== pend) {
      var carry = source[pbegin]
            // Apply "b58 = b58 * 256 + ch".
      var i = 0
      for (var it1 = size - 1; (carry !== 0 || i < length) && (it1 !== -1); it1--, i++) {
        carry += (256 * b58[it1]) >>> 0
        b58[it1] = (carry % BASE) >>> 0
        carry = (carry / BASE) >>> 0
      }
      if (carry !== 0) { throw new Error('Non-zero carry') }
      length = i
      pbegin++
    }
        // Skip leading zeroes in base58 result.
    var it2 = size - length
    while (it2 !== size && b58[it2] === 0) {
      it2++
    }
        // Translate the result into a string.
    var str = LEADER.repeat(zeroes)
    for (; it2 < size; ++it2) { str += ALPHABET.charAt(b58[it2]) }
    return str
  }
  function decodeUnsafe (source) {
    if (typeof source !== 'string') { throw new TypeError('Expected String') }
    if (source.length === 0) { return _Buffer.alloc(0) }
    var psz = 0
        // Skip and count leading '1's.
    var zeroes = 0
    var length = 0
    while (source[psz] === LEADER) {
      zeroes++
      psz++
    }
        // Allocate enough space in big-endian base256 representation.
    var size = (((source.length - psz) * FACTOR) + 1) >>> 0 // log(58) / log(256), rounded up.
    var b256 = new Uint8Array(size)
        // Process the characters.
    while (source[psz]) {
            // Decode character
      var carry = BASE_MAP[source.charCodeAt(psz)]
            // Invalid character
      if (carry === 255) { return }
      var i = 0
      for (var it3 = size - 1; (carry !== 0 || i < length) && (it3 !== -1); it3--, i++) {
        carry += (BASE * b256[it3]) >>> 0
        b256[it3] = (carry % 256) >>> 0
        carry = (carry / 256) >>> 0
      }
      if (carry !== 0) { throw new Error('Non-zero carry') }
      length = i
      psz++
    }
        // Skip leading zeroes in b256.
    var it4 = size - length
    while (it4 !== size && b256[it4] === 0) {
      it4++
    }
    var vch = _Buffer.allocUnsafe(zeroes + (size - it4))
    vch.fill(0x00, 0, zeroes)
    var j = zeroes
    while (it4 !== size) {
      vch[j++] = b256[it4++]
    }
    return vch
  }
  function decode (string) {
    var buffer = decodeUnsafe(string)
    if (buffer) { return buffer }
    throw new Error('Non-base' + BASE + ' character')
  }
  return {
    encode: encode,
    decodeUnsafe: decodeUnsafe,
    decode: decode
  }
}
module.exports = base

},{"safe-buffer":29}],46:[function(require,module,exports){
var basex = require('base-x')
var ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'

module.exports = basex(ALPHABET)

},{"base-x":45}],47:[function(require,module,exports){
'use strict'

var base58 = require('bs58')
var Buffer = require('safe-buffer').Buffer

module.exports = function (checksumFn) {
  // Encode a buffer as a base58-check encoded string
  function encode (payload) {
    var checksum = checksumFn(payload)

    return base58.encode(Buffer.concat([
      payload,
      checksum
    ], payload.length + 4))
  }

  function decodeRaw (buffer) {
    var payload = buffer.slice(0, -4)
    var checksum = buffer.slice(-4)
    var newChecksum = checksumFn(payload)

    if (checksum[0] ^ newChecksum[0] |
        checksum[1] ^ newChecksum[1] |
        checksum[2] ^ newChecksum[2] |
        checksum[3] ^ newChecksum[3]) return

    return payload
  }

  // Decode a base58-check encoded string to a buffer, no result if checksum is wrong
  function decodeUnsafe (string) {
    var buffer = base58.decodeUnsafe(string)
    if (!buffer) return

    return decodeRaw(buffer)
  }

  function decode (string) {
    var buffer = base58.decode(string)
    var payload = decodeRaw(buffer, checksumFn)
    if (!payload) throw new Error('Invalid checksum')
    return payload
  }

  return {
    encode: encode,
    decode: decode,
    decodeUnsafe: decodeUnsafe
  }
}

},{"bs58":46,"safe-buffer":29}],48:[function(require,module,exports){
'use strict'

var createHash = require('create-hash')
var bs58checkBase = require('./base')

// SHA256(SHA256(buffer))
function sha256x2 (buffer) {
  var tmp = createHash('sha256').update(buffer).digest()
  return createHash('sha256').update(tmp).digest()
}

module.exports = bs58checkBase(sha256x2)

},{"./base":47,"create-hash":3}],49:[function(require,module,exports){
'use strict'

exports.byteLength = byteLength
exports.toByteArray = toByteArray
exports.fromByteArray = fromByteArray

var lookup = []
var revLookup = []
var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array

var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
for (var i = 0, len = code.length; i < len; ++i) {
  lookup[i] = code[i]
  revLookup[code.charCodeAt(i)] = i
}

// Support decoding URL-safe base64 strings, as Node.js does.
// See: https://en.wikipedia.org/wiki/Base64#URL_applications
revLookup['-'.charCodeAt(0)] = 62
revLookup['_'.charCodeAt(0)] = 63

function getLens (b64) {
  var len = b64.length

  if (len % 4 > 0) {
    throw new Error('Invalid string. Length must be a multiple of 4')
  }

  // Trim off extra bytes after placeholder bytes are found
  // See: https://github.com/beatgammit/base64-js/issues/42
  var validLen = b64.indexOf('=')
  if (validLen === -1) validLen = len

  var placeHoldersLen = validLen === len
    ? 0
    : 4 - (validLen % 4)

  return [validLen, placeHoldersLen]
}

// base64 is 4/3 + up to two characters of the original data
function byteLength (b64) {
  var lens = getLens(b64)
  var validLen = lens[0]
  var placeHoldersLen = lens[1]
  return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
}

function _byteLength (b64, validLen, placeHoldersLen) {
  return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
}

function toByteArray (b64) {
  var tmp
  var lens = getLens(b64)
  var validLen = lens[0]
  var placeHoldersLen = lens[1]

  var arr = new Arr(_byteLength(b64, validLen, placeHoldersLen))

  var curByte = 0

  // if there are placeholders, only get up to the last complete 4 chars
  var len = placeHoldersLen > 0
    ? validLen - 4
    : validLen

  var i
  for (i = 0; i < len; i += 4) {
    tmp =
      (revLookup[b64.charCodeAt(i)] << 18) |
      (revLookup[b64.charCodeAt(i + 1)] << 12) |
      (revLookup[b64.charCodeAt(i + 2)] << 6) |
      revLookup[b64.charCodeAt(i + 3)]
    arr[curByte++] = (tmp >> 16) & 0xFF
    arr[curByte++] = (tmp >> 8) & 0xFF
    arr[curByte++] = tmp & 0xFF
  }

  if (placeHoldersLen === 2) {
    tmp =
      (revLookup[b64.charCodeAt(i)] << 2) |
      (revLookup[b64.charCodeAt(i + 1)] >> 4)
    arr[curByte++] = tmp & 0xFF
  }

  if (placeHoldersLen === 1) {
    tmp =
      (revLookup[b64.charCodeAt(i)] << 10) |
      (revLookup[b64.charCodeAt(i + 1)] << 4) |
      (revLookup[b64.charCodeAt(i + 2)] >> 2)
    arr[curByte++] = (tmp >> 8) & 0xFF
    arr[curByte++] = tmp & 0xFF
  }

  return arr
}

function tripletToBase64 (num) {
  return lookup[num >> 18 & 0x3F] +
    lookup[num >> 12 & 0x3F] +
    lookup[num >> 6 & 0x3F] +
    lookup[num & 0x3F]
}

function encodeChunk (uint8, start, end) {
  var tmp
  var output = []
  for (var i = start; i < end; i += 3) {
    tmp =
      ((uint8[i] << 16) & 0xFF0000) +
      ((uint8[i + 1] << 8) & 0xFF00) +
      (uint8[i + 2] & 0xFF)
    output.push(tripletToBase64(tmp))
  }
  return output.join('')
}

function fromByteArray (uint8) {
  var tmp
  var len = uint8.length
  var extraBytes = len % 3 // if we have 1 byte left, pad 2 bytes
  var parts = []
  var maxChunkLength = 16383 // must be multiple of 3

  // go through the array every three bytes, we'll deal with trailing stuff later
  for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
    parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength)))
  }

  // pad the end with zeros, but make sure to not forget the extra bytes
  if (extraBytes === 1) {
    tmp = uint8[len - 1]
    parts.push(
      lookup[tmp >> 2] +
      lookup[(tmp << 4) & 0x3F] +
      '=='
    )
  } else if (extraBytes === 2) {
    tmp = (uint8[len - 2] << 8) + uint8[len - 1]
    parts.push(
      lookup[tmp >> 10] +
      lookup[(tmp >> 4) & 0x3F] +
      lookup[(tmp << 2) & 0x3F] +
      '='
    )
  }

  return parts.join('')
}

},{}],50:[function(require,module,exports){

},{}],51:[function(require,module,exports){
(function (Buffer){(function (){
/*!
 * The buffer module from node.js, for the browser.
 *
 * @author   Feross Aboukhadijeh <https://feross.org>
 * @license  MIT
 */
/* eslint-disable no-proto */

'use strict'

var base64 = require('base64-js')
var ieee754 = require('ieee754')

exports.Buffer = Buffer
exports.SlowBuffer = SlowBuffer
exports.INSPECT_MAX_BYTES = 50

var K_MAX_LENGTH = 0x7fffffff
exports.kMaxLength = K_MAX_LENGTH

/**
 * If `Buffer.TYPED_ARRAY_SUPPORT`:
 *   === true    Use Uint8Array implementation (fastest)
 *   === false   Print warning and recommend using `buffer` v4.x which has an Object
 *               implementation (most compatible, even IE6)
 *
 * Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
 * Opera 11.6+, iOS 4.2+.
 *
 * We report that the browser does not support typed arrays if the are not subclassable
 * using __proto__. Firefox 4-29 lacks support for adding new properties to `Uint8Array`
 * (See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438). IE 10 lacks support
 * for __proto__ and has a buggy typed array implementation.
 */
Buffer.TYPED_ARRAY_SUPPORT = typedArraySupport()

if (!Buffer.TYPED_ARRAY_SUPPORT && typeof console !== 'undefined' &&
    typeof console.error === 'function') {
  console.error(
    'This browser lacks typed array (Uint8Array) support which is required by ' +
    '`buffer` v5.x. Use `buffer` v4.x if you require old browser support.'
  )
}

function typedArraySupport () {
  // Can typed array instances can be augmented?
  try {
    var arr = new Uint8Array(1)
    arr.__proto__ = { __proto__: Uint8Array.prototype, foo: function () { return 42 } }
    return arr.foo() === 42
  } catch (e) {
    return false
  }
}

Object.defineProperty(Buffer.prototype, 'parent', {
  enumerable: true,
  get: function () {
    if (!Buffer.isBuffer(this)) return undefined
    return this.buffer
  }
})

Object.defineProperty(Buffer.prototype, 'offset', {
  enumerable: true,
  get: function () {
    if (!Buffer.isBuffer(this)) return undefined
    return this.byteOffset
  }
})

function createBuffer (length) {
  if (length > K_MAX_LENGTH) {
    throw new RangeError('The value "' + length + '" is invalid for option "size"')
  }
  // Return an augmented `Uint8Array` instance
  var buf = new Uint8Array(length)
  buf.__proto__ = Buffer.prototype
  return buf
}

/**
 * The Buffer constructor returns instances of `Uint8Array` that have their
 * prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of
 * `Uint8Array`, so the returned instances will have all the node `Buffer` methods
 * and the `Uint8Array` methods. Square bracket notation works as expected -- it
 * returns a single octet.
 *
 * The `Uint8Array` prototype remains unmodified.
 */

function Buffer (arg, encodingOrOffset, length) {
  // Common case.
  if (typeof arg === 'number') {
    if (typeof encodingOrOffset === 'string') {
      throw new TypeError(
        'The "string" argument must be of type string. Received type number'
      )
    }
    return allocUnsafe(arg)
  }
  return from(arg, encodingOrOffset, length)
}

// Fix subarray() in ES2016. See: https://github.com/feross/buffer/pull/97
if (typeof Symbol !== 'undefined' && Symbol.species != null &&
    Buffer[Symbol.species] === Buffer) {
  Object.defineProperty(Buffer, Symbol.species, {
    value: null,
    configurable: true,
    enumerable: false,
    writable: false
  })
}

Buffer.poolSize = 8192 // not used by this implementation

function from (value, encodingOrOffset, length) {
  if (typeof value === 'string') {
    return fromString(value, encodingOrOffset)
  }

  if (ArrayBuffer.isView(value)) {
    return fromArrayLike(value)
  }

  if (value == null) {
    throw TypeError(
      'The first argument must be one of type string, Buffer, ArrayBuffer, Array, ' +
      'or Array-like Object. Received type ' + (typeof value)
    )
  }

  if (isInstance(value, ArrayBuffer) ||
      (value && isInstance(value.buffer, ArrayBuffer))) {
    return fromArrayBuffer(value, encodingOrOffset, length)
  }

  if (typeof value === 'number') {
    throw new TypeError(
      'The "value" argument must not be of type number. Received type number'
    )
  }

  var valueOf = value.valueOf && value.valueOf()
  if (valueOf != null && valueOf !== value) {
    return Buffer.from(valueOf, encodingOrOffset, length)
  }

  var b = fromObject(value)
  if (b) return b

  if (typeof Symbol !== 'undefined' && Symbol.toPrimitive != null &&
      typeof value[Symbol.toPrimitive] === 'function') {
    return Buffer.from(
      value[Symbol.toPrimitive]('string'), encodingOrOffset, length
    )
  }

  throw new TypeError(
    'The first argument must be one of type string, Buffer, ArrayBuffer, Array, ' +
    'or Array-like Object. Received type ' + (typeof value)
  )
}

/**
 * Functionally equivalent to Buffer(arg, encoding) but throws a TypeError
 * if value is a number.
 * Buffer.from(str[, encoding])
 * Buffer.from(array)
 * Buffer.from(buffer)
 * Buffer.from(arrayBuffer[, byteOffset[, length]])
 **/
Buffer.from = function (value, encodingOrOffset, length) {
  return from(value, encodingOrOffset, length)
}

// Note: Change prototype *after* Buffer.from is defined to workaround Chrome bug:
// https://github.com/feross/buffer/pull/148
Buffer.prototype.__proto__ = Uint8Array.prototype
Buffer.__proto__ = Uint8Array

function assertSize (size) {
  if (typeof size !== 'number') {
    throw new TypeError('"size" argument must be of type number')
  } else if (size < 0) {
    throw new RangeError('The value "' + size + '" is invalid for option "size"')
  }
}

function alloc (size, fill, encoding) {
  assertSize(size)
  if (size <= 0) {
    return createBuffer(size)
  }
  if (fill !== undefined) {
    // Only pay attention to encoding if it's a string. This
    // prevents accidentally sending in a number that would
    // be interpretted as a start offset.
    return typeof encoding === 'string'
      ? createBuffer(size).fill(fill, encoding)
      : createBuffer(size).fill(fill)
  }
  return createBuffer(size)
}

/**
 * Creates a new filled Buffer instance.
 * alloc(size[, fill[, encoding]])
 **/
Buffer.alloc = function (size, fill, encoding) {
  return alloc(size, fill, encoding)
}

function allocUnsafe (size) {
  assertSize(size)
  return createBuffer(size < 0 ? 0 : checked(size) | 0)
}

/**
 * Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance.
 * */
Buffer.allocUnsafe = function (size) {
  return allocUnsafe(size)
}
/**
 * Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance.
 */
Buffer.allocUnsafeSlow = function (size) {
  return allocUnsafe(size)
}

function fromString (string, encoding) {
  if (typeof encoding !== 'string' || encoding === '') {
    encoding = 'utf8'
  }

  if (!Buffer.isEncoding(encoding)) {
    throw new TypeError('Unknown encoding: ' + encoding)
  }

  var length = byteLength(string, encoding) | 0
  var buf = createBuffer(length)

  var actual = buf.write(string, encoding)

  if (actual !== length) {
    // Writing a hex string, for example, that contains invalid characters will
    // cause everything after the first invalid character to be ignored. (e.g.
    // 'abxxcd' will be treated as 'ab')
    buf = buf.slice(0, actual)
  }

  return buf
}

function fromArrayLike (array) {
  var length = array.length < 0 ? 0 : checked(array.length) | 0
  var buf = createBuffer(length)
  for (var i = 0; i < length; i += 1) {
    buf[i] = array[i] & 255
  }
  return buf
}

function fromArrayBuffer (array, byteOffset, length) {
  if (byteOffset < 0 || array.byteLength < byteOffset) {
    throw new RangeError('"offset" is outside of buffer bounds')
  }

  if (array.byteLength < byteOffset + (length || 0)) {
    throw new RangeError('"length" is outside of buffer bounds')
  }

  var buf
  if (byteOffset === undefined && length === undefined) {
    buf = new Uint8Array(array)
  } else if (length === undefined) {
    buf = new Uint8Array(array, byteOffset)
  } else {
    buf = new Uint8Array(array, byteOffset, length)
  }

  // Return an augmented `Uint8Array` instance
  buf.__proto__ = Buffer.prototype
  return buf
}

function fromObject (obj) {
  if (Buffer.isBuffer(obj)) {
    var len = checked(obj.length) | 0
    var buf = createBuffer(len)

    if (buf.length === 0) {
      return buf
    }

    obj.copy(buf, 0, 0, len)
    return buf
  }

  if (obj.length !== undefined) {
    if (typeof obj.length !== 'number' || numberIsNaN(obj.length)) {
      return createBuffer(0)
    }
    return fromArrayLike(obj)
  }

  if (obj.type === 'Buffer' && Array.isArray(obj.data)) {
    return fromArrayLike(obj.data)
  }
}

function checked (length) {
  // Note: cannot use `length < K_MAX_LENGTH` here because that fails when
  // length is NaN (which is otherwise coerced to zero.)
  if (length >= K_MAX_LENGTH) {
    throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
                         'size: 0x' + K_MAX_LENGTH.toString(16) + ' bytes')
  }
  return length | 0
}

function SlowBuffer (length) {
  if (+length != length) { // eslint-disable-line eqeqeq
    length = 0
  }
  return Buffer.alloc(+length)
}

Buffer.isBuffer = function isBuffer (b) {
  return b != null && b._isBuffer === true &&
    b !== Buffer.prototype // so Buffer.isBuffer(Buffer.prototype) will be false
}

Buffer.compare = function compare (a, b) {
  if (isInstance(a, Uint8Array)) a = Buffer.from(a, a.offset, a.byteLength)
  if (isInstance(b, Uint8Array)) b = Buffer.from(b, b.offset, b.byteLength)
  if (!Buffer.isBuffer(a) || !Buffer.isBuffer(b)) {
    throw new TypeError(
      'The "buf1", "buf2" arguments must be one of type Buffer or Uint8Array'
    )
  }

  if (a === b) return 0

  var x = a.length
  var y = b.length

  for (var i = 0, len = Math.min(x, y); i < len; ++i) {
    if (a[i] !== b[i]) {
      x = a[i]
      y = b[i]
      break
    }
  }

  if (x < y) return -1
  if (y < x) return 1
  return 0
}

Buffer.isEncoding = function isEncoding (encoding) {
  switch (String(encoding).toLowerCase()) {
    case 'hex':
    case 'utf8':
    case 'utf-8':
    case 'ascii':
    case 'latin1':
    case 'binary':
    case 'base64':
    case 'ucs2':
    case 'ucs-2':
    case 'utf16le':
    case 'utf-16le':
      return true
    default:
      return false
  }
}

Buffer.concat = function concat (list, length) {
  if (!Array.isArray(list)) {
    throw new TypeError('"list" argument must be an Array of Buffers')
  }

  if (list.length === 0) {
    return Buffer.alloc(0)
  }

  var i
  if (length === undefined) {
    length = 0
    for (i = 0; i < list.length; ++i) {
      length += list[i].length
    }
  }

  var buffer = Buffer.allocUnsafe(length)
  var pos = 0
  for (i = 0; i < list.length; ++i) {
    var buf = list[i]
    if (isInstance(buf, Uint8Array)) {
      buf = Buffer.from(buf)
    }
    if (!Buffer.isBuffer(buf)) {
      throw new TypeError('"list" argument must be an Array of Buffers')
    }
    buf.copy(buffer, pos)
    pos += buf.length
  }
  return buffer
}

function byteLength (string, encoding) {
  if (Buffer.isBuffer(string)) {
    return string.length
  }
  if (ArrayBuffer.isView(string) || isInstance(string, ArrayBuffer)) {
    return string.byteLength
  }
  if (typeof string !== 'string') {
    throw new TypeError(
      'The "string" argument must be one of type string, Buffer, or ArrayBuffer. ' +
      'Received type ' + typeof string
    )
  }

  var len = string.length
  var mustMatch = (arguments.length > 2 && arguments[2] === true)
  if (!mustMatch && len === 0) return 0

  // Use a for loop to avoid recursion
  var loweredCase = false
  for (;;) {
    switch (encoding) {
      case 'ascii':
      case 'latin1':
      case 'binary':
        return len
      case 'utf8':
      case 'utf-8':
        return utf8ToBytes(string).length
      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return len * 2
      case 'hex':
        return len >>> 1
      case 'base64':
        return base64ToBytes(string).length
      default:
        if (loweredCase) {
          return mustMatch ? -1 : utf8ToBytes(string).length // assume utf8
        }
        encoding = ('' + encoding).toLowerCase()
        loweredCase = true
    }
  }
}
Buffer.byteLength = byteLength

function slowToString (encoding, start, end) {
  var loweredCase = false

  // No need to verify that "this.length <= MAX_UINT32" since it's a read-only
  // property of a typed array.

  // This behaves neither like String nor Uint8Array in that we set start/end
  // to their upper/lower bounds if the value passed is out of range.
  // undefined is handled specially as per ECMA-262 6th Edition,
  // Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization.
  if (start === undefined || start < 0) {
    start = 0
  }
  // Return early if start > this.length. Done here to prevent potential uint32
  // coercion fail below.
  if (start > this.length) {
    return ''
  }

  if (end === undefined || end > this.length) {
    end = this.length
  }

  if (end <= 0) {
    return ''
  }

  // Force coersion to uint32. This will also coerce falsey/NaN values to 0.
  end >>>= 0
  start >>>= 0

  if (end <= start) {
    return ''
  }

  if (!encoding) encoding = 'utf8'

  while (true) {
    switch (encoding) {
      case 'hex':
        return hexSlice(this, start, end)

      case 'utf8':
      case 'utf-8':
        return utf8Slice(this, start, end)

      case 'ascii':
        return asciiSlice(this, start, end)

      case 'latin1':
      case 'binary':
        return latin1Slice(this, start, end)

      case 'base64':
        return base64Slice(this, start, end)

      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return utf16leSlice(this, start, end)

      default:
        if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
        encoding = (encoding + '').toLowerCase()
        loweredCase = true
    }
  }
}

// This property is used by `Buffer.isBuffer` (and the `is-buffer` npm package)
// to detect a Buffer instance. It's not possible to use `instanceof Buffer`
// reliably in a browserify context because there could be multiple different
// copies of the 'buffer' package in use. This method works even for Buffer
// instances that were created from another copy of the `buffer` package.
// See: https://github.com/feross/buffer/issues/154
Buffer.prototype._isBuffer = true

function swap (b, n, m) {
  var i = b[n]
  b[n] = b[m]
  b[m] = i
}

Buffer.prototype.swap16 = function swap16 () {
  var len = this.length
  if (len % 2 !== 0) {
    throw new RangeError('Buffer size must be a multiple of 16-bits')
  }
  for (var i = 0; i < len; i += 2) {
    swap(this, i, i + 1)
  }
  return this
}

Buffer.prototype.swap32 = function swap32 () {
  var len = this.length
  if (len % 4 !== 0) {
    throw new RangeError('Buffer size must be a multiple of 32-bits')
  }
  for (var i = 0; i < len; i += 4) {
    swap(this, i, i + 3)
    swap(this, i + 1, i + 2)
  }
  return this
}

Buffer.prototype.swap64 = function swap64 () {
  var len = this.length
  if (len % 8 !== 0) {
    throw new RangeError('Buffer size must be a multiple of 64-bits')
  }
  for (var i = 0; i < len; i += 8) {
    swap(this, i, i + 7)
    swap(this, i + 1, i + 6)
    swap(this, i + 2, i + 5)
    swap(this, i + 3, i + 4)
  }
  return this
}

Buffer.prototype.toString = function toString () {
  var length = this.length
  if (length === 0) return ''
  if (arguments.length === 0) return utf8Slice(this, 0, length)
  return slowToString.apply(this, arguments)
}

Buffer.prototype.toLocaleString = Buffer.prototype.toString

Buffer.prototype.equals = function equals (b) {
  if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
  if (this === b) return true
  return Buffer.compare(this, b) === 0
}

Buffer.prototype.inspect = function inspect () {
  var str = ''
  var max = exports.INSPECT_MAX_BYTES
  str = this.toString('hex', 0, max).replace(/(.{2})/g, '$1 ').trim()
  if (this.length > max) str += ' ... '
  return '<Buffer ' + str + '>'
}

Buffer.prototype.compare = function compare (target, start, end, thisStart, thisEnd) {
  if (isInstance(target, Uint8Array)) {
    target = Buffer.from(target, target.offset, target.byteLength)
  }
  if (!Buffer.isBuffer(target)) {
    throw new TypeError(
      'The "target" argument must be one of type Buffer or Uint8Array. ' +
      'Received type ' + (typeof target)
    )
  }

  if (start === undefined) {
    start = 0
  }
  if (end === undefined) {
    end = target ? target.length : 0
  }
  if (thisStart === undefined) {
    thisStart = 0
  }
  if (thisEnd === undefined) {
    thisEnd = this.length
  }

  if (start < 0 || end > target.length || thisStart < 0 || thisEnd > this.length) {
    throw new RangeError('out of range index')
  }

  if (thisStart >= thisEnd && start >= end) {
    return 0
  }
  if (thisStart >= thisEnd) {
    return -1
  }
  if (start >= end) {
    return 1
  }

  start >>>= 0
  end >>>= 0
  thisStart >>>= 0
  thisEnd >>>= 0

  if (this === target) return 0

  var x = thisEnd - thisStart
  var y = end - start
  var len = Math.min(x, y)

  var thisCopy = this.slice(thisStart, thisEnd)
  var targetCopy = target.slice(start, end)

  for (var i = 0; i < len; ++i) {
    if (thisCopy[i] !== targetCopy[i]) {
      x = thisCopy[i]
      y = targetCopy[i]
      break
    }
  }

  if (x < y) return -1
  if (y < x) return 1
  return 0
}

// Finds either the first index of `val` in `buffer` at offset >= `byteOffset`,
// OR the last index of `val` in `buffer` at offset <= `byteOffset`.
//
// Arguments:
// - buffer - a Buffer to search
// - val - a string, Buffer, or number
// - byteOffset - an index into `buffer`; will be clamped to an int32
// - encoding - an optional encoding, relevant is val is a string
// - dir - true for indexOf, false for lastIndexOf
function bidirectionalIndexOf (buffer, val, byteOffset, encoding, dir) {
  // Empty buffer means no match
  if (buffer.length === 0) return -1

  // Normalize byteOffset
  if (typeof byteOffset === 'string') {
    encoding = byteOffset
    byteOffset = 0
  } else if (byteOffset > 0x7fffffff) {
    byteOffset = 0x7fffffff
  } else if (byteOffset < -0x80000000) {
    byteOffset = -0x80000000
  }
  byteOffset = +byteOffset // Coerce to Number.
  if (numberIsNaN(byteOffset)) {
    // byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer
    byteOffset = dir ? 0 : (buffer.length - 1)
  }

  // Normalize byteOffset: negative offsets start from the end of the buffer
  if (byteOffset < 0) byteOffset = buffer.length + byteOffset
  if (byteOffset >= buffer.length) {
    if (dir) return -1
    else byteOffset = buffer.length - 1
  } else if (byteOffset < 0) {
    if (dir) byteOffset = 0
    else return -1
  }

  // Normalize val
  if (typeof val === 'string') {
    val = Buffer.from(val, encoding)
  }

  // Finally, search either indexOf (if dir is true) or lastIndexOf
  if (Buffer.isBuffer(val)) {
    // Special case: looking for empty string/buffer always fails
    if (val.length === 0) {
      return -1
    }
    return arrayIndexOf(buffer, val, byteOffset, encoding, dir)
  } else if (typeof val === 'number') {
    val = val & 0xFF // Search for a byte value [0-255]
    if (typeof Uint8Array.prototype.indexOf === 'function') {
      if (dir) {
        return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset)
      } else {
        return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset)
      }
    }
    return arrayIndexOf(buffer, [ val ], byteOffset, encoding, dir)
  }

  throw new TypeError('val must be string, number or Buffer')
}

function arrayIndexOf (arr, val, byteOffset, encoding, dir) {
  var indexSize = 1
  var arrLength = arr.length
  var valLength = val.length

  if (encoding !== undefined) {
    encoding = String(encoding).toLowerCase()
    if (encoding === 'ucs2' || encoding === 'ucs-2' ||
        encoding === 'utf16le' || encoding === 'utf-16le') {
      if (arr.length < 2 || val.length < 2) {
        return -1
      }
      indexSize = 2
      arrLength /= 2
      valLength /= 2
      byteOffset /= 2
    }
  }

  function read (buf, i) {
    if (indexSize === 1) {
      return buf[i]
    } else {
      return buf.readUInt16BE(i * indexSize)
    }
  }

  var i
  if (dir) {
    var foundIndex = -1
    for (i = byteOffset; i < arrLength; i++) {
      if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) {
        if (foundIndex === -1) foundIndex = i
        if (i - foundIndex + 1 === valLength) return foundIndex * indexSize
      } else {
        if (foundIndex !== -1) i -= i - foundIndex
        foundIndex = -1
      }
    }
  } else {
    if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength
    for (i = byteOffset; i >= 0; i--) {
      var found = true
      for (var j = 0; j < valLength; j++) {
        if (read(arr, i + j) !== read(val, j)) {
          found = false
          break
        }
      }
      if (found) return i
    }
  }

  return -1
}

Buffer.prototype.includes = function includes (val, byteOffset, encoding) {
  return this.indexOf(val, byteOffset, encoding) !== -1
}

Buffer.prototype.indexOf = function indexOf (val, byteOffset, encoding) {
  return bidirectionalIndexOf(this, val, byteOffset, encoding, true)
}

Buffer.prototype.lastIndexOf = function lastIndexOf (val, byteOffset, encoding) {
  return bidirectionalIndexOf(this, val, byteOffset, encoding, false)
}

function hexWrite (buf, string, offset, length) {
  offset = Number(offset) || 0
  var remaining = buf.length - offset
  if (!length) {
    length = remaining
  } else {
    length = Number(length)
    if (length > remaining) {
      length = remaining
    }
  }

  var strLen = string.length

  if (length > strLen / 2) {
    length = strLen / 2
  }
  for (var i = 0; i < length; ++i) {
    var parsed = parseInt(string.substr(i * 2, 2), 16)
    if (numberIsNaN(parsed)) return i
    buf[offset + i] = parsed
  }
  return i
}

function utf8Write (buf, string, offset, length) {
  return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length)
}

function asciiWrite (buf, string, offset, length) {
  return blitBuffer(asciiToBytes(string), buf, offset, length)
}

function latin1Write (buf, string, offset, length) {
  return asciiWrite(buf, string, offset, length)
}

function base64Write (buf, string, offset, length) {
  return blitBuffer(base64ToBytes(string), buf, offset, length)
}

function ucs2Write (buf, string, offset, length) {
  return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length)
}

Buffer.prototype.write = function write (string, offset, length, encoding) {
  // Buffer#write(string)
  if (offset === undefined) {
    encoding = 'utf8'
    length = this.length
    offset = 0
  // Buffer#write(string, encoding)
  } else if (length === undefined && typeof offset === 'string') {
    encoding = offset
    length = this.length
    offset = 0
  // Buffer#write(string, offset[, length][, encoding])
  } else if (isFinite(offset)) {
    offset = offset >>> 0
    if (isFinite(length)) {
      length = length >>> 0
      if (encoding === undefined) encoding = 'utf8'
    } else {
      encoding = length
      length = undefined
    }
  } else {
    throw new Error(
      'Buffer.write(string, encoding, offset[, length]) is no longer supported'
    )
  }

  var remaining = this.length - offset
  if (length === undefined || length > remaining) length = remaining

  if ((string.length > 0 && (length < 0 || offset < 0)) || offset > this.length) {
    throw new RangeError('Attempt to write outside buffer bounds')
  }

  if (!encoding) encoding = 'utf8'

  var loweredCase = false
  for (;;) {
    switch (encoding) {
      case 'hex':
        return hexWrite(this, string, offset, length)

      case 'utf8':
      case 'utf-8':
        return utf8Write(this, string, offset, length)

      case 'ascii':
        return asciiWrite(this, string, offset, length)

      case 'latin1':
      case 'binary':
        return latin1Write(this, string, offset, length)

      case 'base64':
        // Warning: maxLength not taken into account in base64Write
        return base64Write(this, string, offset, length)

      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return ucs2Write(this, string, offset, length)

      default:
        if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
        encoding = ('' + encoding).toLowerCase()
        loweredCase = true
    }
  }
}

Buffer.prototype.toJSON = function toJSON () {
  return {
    type: 'Buffer',
    data: Array.prototype.slice.call(this._arr || this, 0)
  }
}

function base64Slice (buf, start, end) {
  if (start === 0 && end === buf.length) {
    return base64.fromByteArray(buf)
  } else {
    return base64.fromByteArray(buf.slice(start, end))
  }
}

function utf8Slice (buf, start, end) {
  end = Math.min(buf.length, end)
  var res = []

  var i = start
  while (i < end) {
    var firstByte = buf[i]
    var codePoint = null
    var bytesPerSequence = (firstByte > 0xEF) ? 4
      : (firstByte > 0xDF) ? 3
        : (firstByte > 0xBF) ? 2
          : 1

    if (i + bytesPerSequence <= end) {
      var secondByte, thirdByte, fourthByte, tempCodePoint

      switch (bytesPerSequence) {
        case 1:
          if (firstByte < 0x80) {
            codePoint = firstByte
          }
          break
        case 2:
          secondByte = buf[i + 1]
          if ((secondByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0x1F) << 0x6 | (secondByte & 0x3F)
            if (tempCodePoint > 0x7F) {
              codePoint = tempCodePoint
            }
          }
          break
        case 3:
          secondByte = buf[i + 1]
          thirdByte = buf[i + 2]
          if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | (thirdByte & 0x3F)
            if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) {
              codePoint = tempCodePoint
            }
          }
          break
        case 4:
          secondByte = buf[i + 1]
          thirdByte = buf[i + 2]
          fourthByte = buf[i + 3]
          if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) {
            tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | (fourthByte & 0x3F)
            if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) {
              codePoint = tempCodePoint
            }
          }
      }
    }

    if (codePoint === null) {
      // we did not generate a valid codePoint so insert a
      // replacement char (U+FFFD) and advance only 1 byte
      codePoint = 0xFFFD
      bytesPerSequence = 1
    } else if (codePoint > 0xFFFF) {
      // encode to utf16 (surrogate pair dance)
      codePoint -= 0x10000
      res.push(codePoint >>> 10 & 0x3FF | 0xD800)
      codePoint = 0xDC00 | codePoint & 0x3FF
    }

    res.push(codePoint)
    i += bytesPerSequence
  }

  return decodeCodePointsArray(res)
}

// Based on http://stackoverflow.com/a/22747272/680742, the browser with
// the lowest limit is Chrome, with 0x10000 args.
// We go 1 magnitude less, for safety
var MAX_ARGUMENTS_LENGTH = 0x1000

function decodeCodePointsArray (codePoints) {
  var len = codePoints.length
  if (len <= MAX_ARGUMENTS_LENGTH) {
    return String.fromCharCode.apply(String, codePoints) // avoid extra slice()
  }

  // Decode in chunks to avoid "call stack size exceeded".
  var res = ''
  var i = 0
  while (i < len) {
    res += String.fromCharCode.apply(
      String,
      codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH)
    )
  }
  return res
}

function asciiSlice (buf, start, end) {
  var ret = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; ++i) {
    ret += String.fromCharCode(buf[i] & 0x7F)
  }
  return ret
}

function latin1Slice (buf, start, end) {
  var ret = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; ++i) {
    ret += String.fromCharCode(buf[i])
  }
  return ret
}

function hexSlice (buf, start, end) {
  var len = buf.length

  if (!start || start < 0) start = 0
  if (!end || end < 0 || end > len) end = len

  var out = ''
  for (var i = start; i < end; ++i) {
    out += toHex(buf[i])
  }
  return out
}

function utf16leSlice (buf, start, end) {
  var bytes = buf.slice(start, end)
  var res = ''
  for (var i = 0; i < bytes.length; i += 2) {
    res += String.fromCharCode(bytes[i] + (bytes[i + 1] * 256))
  }
  return res
}

Buffer.prototype.slice = function slice (start, end) {
  var len = this.length
  start = ~~start
  end = end === undefined ? len : ~~end

  if (start < 0) {
    start += len
    if (start < 0) start = 0
  } else if (start > len) {
    start = len
  }

  if (end < 0) {
    end += len
    if (end < 0) end = 0
  } else if (end > len) {
    end = len
  }

  if (end < start) end = start

  var newBuf = this.subarray(start, end)
  // Return an augmented `Uint8Array` instance
  newBuf.__proto__ = Buffer.prototype
  return newBuf
}

/*
 * Need to make sure that buffer isn't trying to write out of bounds.
 */
function checkOffset (offset, ext, length) {
  if ((offset % 1) !== 0 || offset < 0) throw new RangeError('offset is not uint')
  if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length')
}

Buffer.prototype.readUIntLE = function readUIntLE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var val = this[offset]
  var mul = 1
  var i = 0
  while (++i < byteLength && (mul *= 0x100)) {
    val += this[offset + i] * mul
  }

  return val
}

Buffer.prototype.readUIntBE = function readUIntBE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) {
    checkOffset(offset, byteLength, this.length)
  }

  var val = this[offset + --byteLength]
  var mul = 1
  while (byteLength > 0 && (mul *= 0x100)) {
    val += this[offset + --byteLength] * mul
  }

  return val
}

Buffer.prototype.readUInt8 = function readUInt8 (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 1, this.length)
  return this[offset]
}

Buffer.prototype.readUInt16LE = function readUInt16LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  return this[offset] | (this[offset + 1] << 8)
}

Buffer.prototype.readUInt16BE = function readUInt16BE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  return (this[offset] << 8) | this[offset + 1]
}

Buffer.prototype.readUInt32LE = function readUInt32LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)

  return ((this[offset]) |
      (this[offset + 1] << 8) |
      (this[offset + 2] << 16)) +
      (this[offset + 3] * 0x1000000)
}

Buffer.prototype.readUInt32BE = function readUInt32BE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset] * 0x1000000) +
    ((this[offset + 1] << 16) |
    (this[offset + 2] << 8) |
    this[offset + 3])
}

Buffer.prototype.readIntLE = function readIntLE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var val = this[offset]
  var mul = 1
  var i = 0
  while (++i < byteLength && (mul *= 0x100)) {
    val += this[offset + i] * mul
  }
  mul *= 0x80

  if (val >= mul) val -= Math.pow(2, 8 * byteLength)

  return val
}

Buffer.prototype.readIntBE = function readIntBE (offset, byteLength, noAssert) {
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) checkOffset(offset, byteLength, this.length)

  var i = byteLength
  var mul = 1
  var val = this[offset + --i]
  while (i > 0 && (mul *= 0x100)) {
    val += this[offset + --i] * mul
  }
  mul *= 0x80

  if (val >= mul) val -= Math.pow(2, 8 * byteLength)

  return val
}

Buffer.prototype.readInt8 = function readInt8 (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 1, this.length)
  if (!(this[offset] & 0x80)) return (this[offset])
  return ((0xff - this[offset] + 1) * -1)
}

Buffer.prototype.readInt16LE = function readInt16LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  var val = this[offset] | (this[offset + 1] << 8)
  return (val & 0x8000) ? val | 0xFFFF0000 : val
}

Buffer.prototype.readInt16BE = function readInt16BE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 2, this.length)
  var val = this[offset + 1] | (this[offset] << 8)
  return (val & 0x8000) ? val | 0xFFFF0000 : val
}

Buffer.prototype.readInt32LE = function readInt32LE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset]) |
    (this[offset + 1] << 8) |
    (this[offset + 2] << 16) |
    (this[offset + 3] << 24)
}

Buffer.prototype.readInt32BE = function readInt32BE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)

  return (this[offset] << 24) |
    (this[offset + 1] << 16) |
    (this[offset + 2] << 8) |
    (this[offset + 3])
}

Buffer.prototype.readFloatLE = function readFloatLE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)
  return ieee754.read(this, offset, true, 23, 4)
}

Buffer.prototype.readFloatBE = function readFloatBE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 4, this.length)
  return ieee754.read(this, offset, false, 23, 4)
}

Buffer.prototype.readDoubleLE = function readDoubleLE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 8, this.length)
  return ieee754.read(this, offset, true, 52, 8)
}

Buffer.prototype.readDoubleBE = function readDoubleBE (offset, noAssert) {
  offset = offset >>> 0
  if (!noAssert) checkOffset(offset, 8, this.length)
  return ieee754.read(this, offset, false, 52, 8)
}

function checkInt (buf, value, offset, ext, max, min) {
  if (!Buffer.isBuffer(buf)) throw new TypeError('"buffer" argument must be a Buffer instance')
  if (value > max || value < min) throw new RangeError('"value" argument is out of bounds')
  if (offset + ext > buf.length) throw new RangeError('Index out of range')
}

Buffer.prototype.writeUIntLE = function writeUIntLE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) {
    var maxBytes = Math.pow(2, 8 * byteLength) - 1
    checkInt(this, value, offset, byteLength, maxBytes, 0)
  }

  var mul = 1
  var i = 0
  this[offset] = value & 0xFF
  while (++i < byteLength && (mul *= 0x100)) {
    this[offset + i] = (value / mul) & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeUIntBE = function writeUIntBE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset >>> 0
  byteLength = byteLength >>> 0
  if (!noAssert) {
    var maxBytes = Math.pow(2, 8 * byteLength) - 1
    checkInt(this, value, offset, byteLength, maxBytes, 0)
  }

  var i = byteLength - 1
  var mul = 1
  this[offset + i] = value & 0xFF
  while (--i >= 0 && (mul *= 0x100)) {
    this[offset + i] = (value / mul) & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeUInt8 = function writeUInt8 (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 1, 0xff, 0)
  this[offset] = (value & 0xff)
  return offset + 1
}

Buffer.prototype.writeUInt16LE = function writeUInt16LE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
  this[offset] = (value & 0xff)
  this[offset + 1] = (value >>> 8)
  return offset + 2
}

Buffer.prototype.writeUInt16BE = function writeUInt16BE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
  this[offset] = (value >>> 8)
  this[offset + 1] = (value & 0xff)
  return offset + 2
}

Buffer.prototype.writeUInt32LE = function writeUInt32LE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
  this[offset + 3] = (value >>> 24)
  this[offset + 2] = (value >>> 16)
  this[offset + 1] = (value >>> 8)
  this[offset] = (value & 0xff)
  return offset + 4
}

Buffer.prototype.writeUInt32BE = function writeUInt32BE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
  this[offset] = (value >>> 24)
  this[offset + 1] = (value >>> 16)
  this[offset + 2] = (value >>> 8)
  this[offset + 3] = (value & 0xff)
  return offset + 4
}

Buffer.prototype.writeIntLE = function writeIntLE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) {
    var limit = Math.pow(2, (8 * byteLength) - 1)

    checkInt(this, value, offset, byteLength, limit - 1, -limit)
  }

  var i = 0
  var mul = 1
  var sub = 0
  this[offset] = value & 0xFF
  while (++i < byteLength && (mul *= 0x100)) {
    if (value < 0 && sub === 0 && this[offset + i - 1] !== 0) {
      sub = 1
    }
    this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeIntBE = function writeIntBE (value, offset, byteLength, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) {
    var limit = Math.pow(2, (8 * byteLength) - 1)

    checkInt(this, value, offset, byteLength, limit - 1, -limit)
  }

  var i = byteLength - 1
  var mul = 1
  var sub = 0
  this[offset + i] = value & 0xFF
  while (--i >= 0 && (mul *= 0x100)) {
    if (value < 0 && sub === 0 && this[offset + i + 1] !== 0) {
      sub = 1
    }
    this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
  }

  return offset + byteLength
}

Buffer.prototype.writeInt8 = function writeInt8 (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 1, 0x7f, -0x80)
  if (value < 0) value = 0xff + value + 1
  this[offset] = (value & 0xff)
  return offset + 1
}

Buffer.prototype.writeInt16LE = function writeInt16LE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
  this[offset] = (value & 0xff)
  this[offset + 1] = (value >>> 8)
  return offset + 2
}

Buffer.prototype.writeInt16BE = function writeInt16BE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
  this[offset] = (value >>> 8)
  this[offset + 1] = (value & 0xff)
  return offset + 2
}

Buffer.prototype.writeInt32LE = function writeInt32LE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
  this[offset] = (value & 0xff)
  this[offset + 1] = (value >>> 8)
  this[offset + 2] = (value >>> 16)
  this[offset + 3] = (value >>> 24)
  return offset + 4
}

Buffer.prototype.writeInt32BE = function writeInt32BE (value, offset, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
  if (value < 0) value = 0xffffffff + value + 1
  this[offset] = (value >>> 24)
  this[offset + 1] = (value >>> 16)
  this[offset + 2] = (value >>> 8)
  this[offset + 3] = (value & 0xff)
  return offset + 4
}

function checkIEEE754 (buf, value, offset, ext, max, min) {
  if (offset + ext > buf.length) throw new RangeError('Index out of range')
  if (offset < 0) throw new RangeError('Index out of range')
}

function writeFloat (buf, value, offset, littleEndian, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) {
    checkIEEE754(buf, value, offset, 4, 3.4028234663852886e+38, -3.4028234663852886e+38)
  }
  ieee754.write(buf, value, offset, littleEndian, 23, 4)
  return offset + 4
}

Buffer.prototype.writeFloatLE = function writeFloatLE (value, offset, noAssert) {
  return writeFloat(this, value, offset, true, noAssert)
}

Buffer.prototype.writeFloatBE = function writeFloatBE (value, offset, noAssert) {
  return writeFloat(this, value, offset, false, noAssert)
}

function writeDouble (buf, value, offset, littleEndian, noAssert) {
  value = +value
  offset = offset >>> 0
  if (!noAssert) {
    checkIEEE754(buf, value, offset, 8, 1.7976931348623157E+308, -1.7976931348623157E+308)
  }
  ieee754.write(buf, value, offset, littleEndian, 52, 8)
  return offset + 8
}

Buffer.prototype.writeDoubleLE = function writeDoubleLE (value, offset, noAssert) {
  return writeDouble(this, value, offset, true, noAssert)
}

Buffer.prototype.writeDoubleBE = function writeDoubleBE (value, offset, noAssert) {
  return writeDouble(this, value, offset, false, noAssert)
}

// copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)
Buffer.prototype.copy = function copy (target, targetStart, start, end) {
  if (!Buffer.isBuffer(target)) throw new TypeError('argument should be a Buffer')
  if (!start) start = 0
  if (!end && end !== 0) end = this.length
  if (targetStart >= target.length) targetStart = target.length
  if (!targetStart) targetStart = 0
  if (end > 0 && end < start) end = start

  // Copy 0 bytes; we're done
  if (end === start) return 0
  if (target.length === 0 || this.length === 0) return 0

  // Fatal error conditions
  if (targetStart < 0) {
    throw new RangeError('targetStart out of bounds')
  }
  if (start < 0 || start >= this.length) throw new RangeError('Index out of range')
  if (end < 0) throw new RangeError('sourceEnd out of bounds')

  // Are we oob?
  if (end > this.length) end = this.length
  if (target.length - targetStart < end - start) {
    end = target.length - targetStart + start
  }

  var len = end - start

  if (this === target && typeof Uint8Array.prototype.copyWithin === 'function') {
    // Use built-in when available, missing from IE11
    this.copyWithin(targetStart, start, end)
  } else if (this === target && start < targetStart && targetStart < end) {
    // descending copy from end
    for (var i = len - 1; i >= 0; --i) {
      target[i + targetStart] = this[i + start]
    }
  } else {
    Uint8Array.prototype.set.call(
      target,
      this.subarray(start, end),
      targetStart
    )
  }

  return len
}

// Usage:
//    buffer.fill(number[, offset[, end]])
//    buffer.fill(buffer[, offset[, end]])
//    buffer.fill(string[, offset[, end]][, encoding])
Buffer.prototype.fill = function fill (val, start, end, encoding) {
  // Handle string cases:
  if (typeof val === 'string') {
    if (typeof start === 'string') {
      encoding = start
      start = 0
      end = this.length
    } else if (typeof end === 'string') {
      encoding = end
      end = this.length
    }
    if (encoding !== undefined && typeof encoding !== 'string') {
      throw new TypeError('encoding must be a string')
    }
    if (typeof encoding === 'string' && !Buffer.isEncoding(encoding)) {
      throw new TypeError('Unknown encoding: ' + encoding)
    }
    if (val.length === 1) {
      var code = val.charCodeAt(0)
      if ((encoding === 'utf8' && code < 128) ||
          encoding === 'latin1') {
        // Fast path: If `val` fits into a single byte, use that numeric value.
        val = code
      }
    }
  } else if (typeof val === 'number') {
    val = val & 255
  }

  // Invalid ranges are not set to a default, so can range check early.
  if (start < 0 || this.length < start || this.length < end) {
    throw new RangeError('Out of range index')
  }

  if (end <= start) {
    return this
  }

  start = start >>> 0
  end = end === undefined ? this.length : end >>> 0

  if (!val) val = 0

  var i
  if (typeof val === 'number') {
    for (i = start; i < end; ++i) {
      this[i] = val
    }
  } else {
    var bytes = Buffer.isBuffer(val)
      ? val
      : Buffer.from(val, encoding)
    var len = bytes.length
    if (len === 0) {
      throw new TypeError('The value "' + val +
        '" is invalid for argument "value"')
    }
    for (i = 0; i < end - start; ++i) {
      this[i + start] = bytes[i % len]
    }
  }

  return this
}

// HELPER FUNCTIONS
// ================

var INVALID_BASE64_RE = /[^+/0-9A-Za-z-_]/g

function base64clean (str) {
  // Node takes equal signs as end of the Base64 encoding
  str = str.split('=')[0]
  // Node strips out invalid characters like \n and \t from the string, base64-js does not
  str = str.trim().replace(INVALID_BASE64_RE, '')
  // Node converts strings with length < 2 to ''
  if (str.length < 2) return ''
  // Node allows for non-padded base64 strings (missing trailing ===), base64-js does not
  while (str.length % 4 !== 0) {
    str = str + '='
  }
  return str
}

function toHex (n) {
  if (n < 16) return '0' + n.toString(16)
  return n.toString(16)
}

function utf8ToBytes (string, units) {
  units = units || Infinity
  var codePoint
  var length = string.length
  var leadSurrogate = null
  var bytes = []

  for (var i = 0; i < length; ++i) {
    codePoint = string.charCodeAt(i)

    // is surrogate component
    if (codePoint > 0xD7FF && codePoint < 0xE000) {
      // last char was a lead
      if (!leadSurrogate) {
        // no lead yet
        if (codePoint > 0xDBFF) {
          // unexpected trail
          if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
          continue
        } else if (i + 1 === length) {
          // unpaired lead
          if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
          continue
        }

        // valid lead
        leadSurrogate = codePoint

        continue
      }

      // 2 leads in a row
      if (codePoint < 0xDC00) {
        if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
        leadSurrogate = codePoint
        continue
      }

      // valid surrogate pair
      codePoint = (leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00) + 0x10000
    } else if (leadSurrogate) {
      // valid bmp char, but last char was a lead
      if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
    }

    leadSurrogate = null

    // encode utf8
    if (codePoint < 0x80) {
      if ((units -= 1) < 0) break
      bytes.push(codePoint)
    } else if (codePoint < 0x800) {
      if ((units -= 2) < 0) break
      bytes.push(
        codePoint >> 0x6 | 0xC0,
        codePoint & 0x3F | 0x80
      )
    } else if (codePoint < 0x10000) {
      if ((units -= 3) < 0) break
      bytes.push(
        codePoint >> 0xC | 0xE0,
        codePoint >> 0x6 & 0x3F | 0x80,
        codePoint & 0x3F | 0x80
      )
    } else if (codePoint < 0x110000) {
      if ((units -= 4) < 0) break
      bytes.push(
        codePoint >> 0x12 | 0xF0,
        codePoint >> 0xC & 0x3F | 0x80,
        codePoint >> 0x6 & 0x3F | 0x80,
        codePoint & 0x3F | 0x80
      )
    } else {
      throw new Error('Invalid code point')
    }
  }

  return bytes
}

function asciiToBytes (str) {
  var byteArray = []
  for (var i = 0; i < str.length; ++i) {
    // Node's code seems to be doing this and not & 0x7F..
    byteArray.push(str.charCodeAt(i) & 0xFF)
  }
  return byteArray
}

function utf16leToBytes (str, units) {
  var c, hi, lo
  var byteArray = []
  for (var i = 0; i < str.length; ++i) {
    if ((units -= 2) < 0) break

    c = str.charCodeAt(i)
    hi = c >> 8
    lo = c % 256
    byteArray.push(lo)
    byteArray.push(hi)
  }

  return byteArray
}

function base64ToBytes (str) {
  return base64.toByteArray(base64clean(str))
}

function blitBuffer (src, dst, offset, length) {
  for (var i = 0; i < length; ++i) {
    if ((i + offset >= dst.length) || (i >= src.length)) break
    dst[i + offset] = src[i]
  }
  return i
}

// ArrayBuffer or Uint8Array objects from other contexts (i.e. iframes) do not pass
// the `instanceof` check but they should be treated as of that type.
// See: https://github.com/feross/buffer/issues/166
function isInstance (obj, type) {
  return obj instanceof type ||
    (obj != null && obj.constructor != null && obj.constructor.name != null &&
      obj.constructor.name === type.name)
}
function numberIsNaN (obj) {
  // For IE11 support
  return obj !== obj // eslint-disable-line no-self-compare
}

}).call(this)}).call(this,require("buffer").Buffer)
},{"base64-js":49,"buffer":51,"ieee754":53}],52:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

var R = typeof Reflect === 'object' ? Reflect : null
var ReflectApply = R && typeof R.apply === 'function'
  ? R.apply
  : function ReflectApply(target, receiver, args) {
    return Function.prototype.apply.call(target, receiver, args);
  }

var ReflectOwnKeys
if (R && typeof R.ownKeys === 'function') {
  ReflectOwnKeys = R.ownKeys
} else if (Object.getOwnPropertySymbols) {
  ReflectOwnKeys = function ReflectOwnKeys(target) {
    return Object.getOwnPropertyNames(target)
      .concat(Object.getOwnPropertySymbols(target));
  };
} else {
  ReflectOwnKeys = function ReflectOwnKeys(target) {
    return Object.getOwnPropertyNames(target);
  };
}

function ProcessEmitWarning(warning) {
  if (console && console.warn) console.warn(warning);
}

var NumberIsNaN = Number.isNaN || function NumberIsNaN(value) {
  return value !== value;
}

function EventEmitter() {
  EventEmitter.init.call(this);
}
module.exports = EventEmitter;
module.exports.once = once;

// Backwards-compat with node 0.10.x
EventEmitter.EventEmitter = EventEmitter;

EventEmitter.prototype._events = undefined;
EventEmitter.prototype._eventsCount = 0;
EventEmitter.prototype._maxListeners = undefined;

// By default EventEmitters will print a warning if more than 10 listeners are
// added to it. This is a useful default which helps finding memory leaks.
var defaultMaxListeners = 10;

function checkListener(listener) {
  if (typeof listener !== 'function') {
    throw new TypeError('The "listener" argument must be of type Function. Received type ' + typeof listener);
  }
}

Object.defineProperty(EventEmitter, 'defaultMaxListeners', {
  enumerable: true,
  get: function() {
    return defaultMaxListeners;
  },
  set: function(arg) {
    if (typeof arg !== 'number' || arg < 0 || NumberIsNaN(arg)) {
      throw new RangeError('The value of "defaultMaxListeners" is out of range. It must be a non-negative number. Received ' + arg + '.');
    }
    defaultMaxListeners = arg;
  }
});

EventEmitter.init = function() {

  if (this._events === undefined ||
      this._events === Object.getPrototypeOf(this)._events) {
    this._events = Object.create(null);
    this._eventsCount = 0;
  }

  this._maxListeners = this._maxListeners || undefined;
};

// Obviously not all Emitters should be limited to 10. This function allows
// that to be increased. Set to zero for unlimited.
EventEmitter.prototype.setMaxListeners = function setMaxListeners(n) {
  if (typeof n !== 'number' || n < 0 || NumberIsNaN(n)) {
    throw new RangeError('The value of "n" is out of range. It must be a non-negative number. Received ' + n + '.');
  }
  this._maxListeners = n;
  return this;
};

function _getMaxListeners(that) {
  if (that._maxListeners === undefined)
    return EventEmitter.defaultMaxListeners;
  return that._maxListeners;
}

EventEmitter.prototype.getMaxListeners = function getMaxListeners() {
  return _getMaxListeners(this);
};

EventEmitter.prototype.emit = function emit(type) {
  var args = [];
  for (var i = 1; i < arguments.length; i++) args.push(arguments[i]);
  var doError = (type === 'error');

  var events = this._events;
  if (events !== undefined)
    doError = (doError && events.error === undefined);
  else if (!doError)
    return false;

  // If there is no 'error' event listener then throw.
  if (doError) {
    var er;
    if (args.length > 0)
      er = args[0];
    if (er instanceof Error) {
      // Note: The comments on the `throw` lines are intentional, they show
      // up in Node's output if this results in an unhandled exception.
      throw er; // Unhandled 'error' event
    }
    // At least give some kind of context to the user
    var err = new Error('Unhandled error.' + (er ? ' (' + er.message + ')' : ''));
    err.context = er;
    throw err; // Unhandled 'error' event
  }

  var handler = events[type];

  if (handler === undefined)
    return false;

  if (typeof handler === 'function') {
    ReflectApply(handler, this, args);
  } else {
    var len = handler.length;
    var listeners = arrayClone(handler, len);
    for (var i = 0; i < len; ++i)
      ReflectApply(listeners[i], this, args);
  }

  return true;
};

function _addListener(target, type, listener, prepend) {
  var m;
  var events;
  var existing;

  checkListener(listener);

  events = target._events;
  if (events === undefined) {
    events = target._events = Object.create(null);
    target._eventsCount = 0;
  } else {
    // To avoid recursion in the case that type === "newListener"! Before
    // adding it to the listeners, first emit "newListener".
    if (events.newListener !== undefined) {
      target.emit('newListener', type,
                  listener.listener ? listener.listener : listener);

      // Re-assign `events` because a newListener handler could have caused the
      // this._events to be assigned to a new object
      events = target._events;
    }
    existing = events[type];
  }

  if (existing === undefined) {
    // Optimize the case of one listener. Don't need the extra array object.
    existing = events[type] = listener;
    ++target._eventsCount;
  } else {
    if (typeof existing === 'function') {
      // Adding the second element, need to change to array.
      existing = events[type] =
        prepend ? [listener, existing] : [existing, listener];
      // If we've already got an array, just append.
    } else if (prepend) {
      existing.unshift(listener);
    } else {
      existing.push(listener);
    }

    // Check for listener leak
    m = _getMaxListeners(target);
    if (m > 0 && existing.length > m && !existing.warned) {
      existing.warned = true;
      // No error code for this since it is a Warning
      // eslint-disable-next-line no-restricted-syntax
      var w = new Error('Possible EventEmitter memory leak detected. ' +
                          existing.length + ' ' + String(type) + ' listeners ' +
                          'added. Use emitter.setMaxListeners() to ' +
                          'increase limit');
      w.name = 'MaxListenersExceededWarning';
      w.emitter = target;
      w.type = type;
      w.count = existing.length;
      ProcessEmitWarning(w);
    }
  }

  return target;
}

EventEmitter.prototype.addListener = function addListener(type, listener) {
  return _addListener(this, type, listener, false);
};

EventEmitter.prototype.on = EventEmitter.prototype.addListener;

EventEmitter.prototype.prependListener =
    function prependListener(type, listener) {
      return _addListener(this, type, listener, true);
    };

function onceWrapper() {
  if (!this.fired) {
    this.target.removeListener(this.type, this.wrapFn);
    this.fired = true;
    if (arguments.length === 0)
      return this.listener.call(this.target);
    return this.listener.apply(this.target, arguments);
  }
}

function _onceWrap(target, type, listener) {
  var state = { fired: false, wrapFn: undefined, target: target, type: type, listener: listener };
  var wrapped = onceWrapper.bind(state);
  wrapped.listener = listener;
  state.wrapFn = wrapped;
  return wrapped;
}

EventEmitter.prototype.once = function once(type, listener) {
  checkListener(listener);
  this.on(type, _onceWrap(this, type, listener));
  return this;
};

EventEmitter.prototype.prependOnceListener =
    function prependOnceListener(type, listener) {
      checkListener(listener);
      this.prependListener(type, _onceWrap(this, type, listener));
      return this;
    };

// Emits a 'removeListener' event if and only if the listener was removed.
EventEmitter.prototype.removeListener =
    function removeListener(type, listener) {
      var list, events, position, i, originalListener;

      checkListener(listener);

      events = this._events;
      if (events === undefined)
        return this;

      list = events[type];
      if (list === undefined)
        return this;

      if (list === listener || list.listener === listener) {
        if (--this._eventsCount === 0)
          this._events = Object.create(null);
        else {
          delete events[type];
          if (events.removeListener)
            this.emit('removeListener', type, list.listener || listener);
        }
      } else if (typeof list !== 'function') {
        position = -1;

        for (i = list.length - 1; i >= 0; i--) {
          if (list[i] === listener || list[i].listener === listener) {
            originalListener = list[i].listener;
            position = i;
            break;
          }
        }

        if (position < 0)
          return this;

        if (position === 0)
          list.shift();
        else {
          spliceOne(list, position);
        }

        if (list.length === 1)
          events[type] = list[0];

        if (events.removeListener !== undefined)
          this.emit('removeListener', type, originalListener || listener);
      }

      return this;
    };

EventEmitter.prototype.off = EventEmitter.prototype.removeListener;

EventEmitter.prototype.removeAllListeners =
    function removeAllListeners(type) {
      var listeners, events, i;

      events = this._events;
      if (events === undefined)
        return this;

      // not listening for removeListener, no need to emit
      if (events.removeListener === undefined) {
        if (arguments.length === 0) {
          this._events = Object.create(null);
          this._eventsCount = 0;
        } else if (events[type] !== undefined) {
          if (--this._eventsCount === 0)
            this._events = Object.create(null);
          else
            delete events[type];
        }
        return this;
      }

      // emit removeListener for all listeners on all events
      if (arguments.length === 0) {
        var keys = Object.keys(events);
        var key;
        for (i = 0; i < keys.length; ++i) {
          key = keys[i];
          if (key === 'removeListener') continue;
          this.removeAllListeners(key);
        }
        this.removeAllListeners('removeListener');
        this._events = Object.create(null);
        this._eventsCount = 0;
        return this;
      }

      listeners = events[type];

      if (typeof listeners === 'function') {
        this.removeListener(type, listeners);
      } else if (listeners !== undefined) {
        // LIFO order
        for (i = listeners.length - 1; i >= 0; i--) {
          this.removeListener(type, listeners[i]);
        }
      }

      return this;
    };

function _listeners(target, type, unwrap) {
  var events = target._events;

  if (events === undefined)
    return [];

  var evlistener = events[type];
  if (evlistener === undefined)
    return [];

  if (typeof evlistener === 'function')
    return unwrap ? [evlistener.listener || evlistener] : [evlistener];

  return unwrap ?
    unwrapListeners(evlistener) : arrayClone(evlistener, evlistener.length);
}

EventEmitter.prototype.listeners = function listeners(type) {
  return _listeners(this, type, true);
};

EventEmitter.prototype.rawListeners = function rawListeners(type) {
  return _listeners(this, type, false);
};

EventEmitter.listenerCount = function(emitter, type) {
  if (typeof emitter.listenerCount === 'function') {
    return emitter.listenerCount(type);
  } else {
    return listenerCount.call(emitter, type);
  }
};

EventEmitter.prototype.listenerCount = listenerCount;
function listenerCount(type) {
  var events = this._events;

  if (events !== undefined) {
    var evlistener = events[type];

    if (typeof evlistener === 'function') {
      return 1;
    } else if (evlistener !== undefined) {
      return evlistener.length;
    }
  }

  return 0;
}

EventEmitter.prototype.eventNames = function eventNames() {
  return this._eventsCount > 0 ? ReflectOwnKeys(this._events) : [];
};

function arrayClone(arr, n) {
  var copy = new Array(n);
  for (var i = 0; i < n; ++i)
    copy[i] = arr[i];
  return copy;
}

function spliceOne(list, index) {
  for (; index + 1 < list.length; index++)
    list[index] = list[index + 1];
  list.pop();
}

function unwrapListeners(arr) {
  var ret = new Array(arr.length);
  for (var i = 0; i < ret.length; ++i) {
    ret[i] = arr[i].listener || arr[i];
  }
  return ret;
}

function once(emitter, name) {
  return new Promise(function (resolve, reject) {
    function errorListener(err) {
      emitter.removeListener(name, resolver);
      reject(err);
    }

    function resolver() {
      if (typeof emitter.removeListener === 'function') {
        emitter.removeListener('error', errorListener);
      }
      resolve([].slice.call(arguments));
    };

    eventTargetAgnosticAddListener(emitter, name, resolver, { once: true });
    if (name !== 'error') {
      addErrorHandlerIfEventEmitter(emitter, errorListener, { once: true });
    }
  });
}

function addErrorHandlerIfEventEmitter(emitter, handler, flags) {
  if (typeof emitter.on === 'function') {
    eventTargetAgnosticAddListener(emitter, 'error', handler, flags);
  }
}

function eventTargetAgnosticAddListener(emitter, name, listener, flags) {
  if (typeof emitter.on === 'function') {
    if (flags.once) {
      emitter.once(name, listener);
    } else {
      emitter.on(name, listener);
    }
  } else if (typeof emitter.addEventListener === 'function') {
    // EventTarget does not have `error` event semantics like Node
    // EventEmitters, we do not listen for `error` events here.
    emitter.addEventListener(name, function wrapListener(arg) {
      // IE does not have builtin `{ once: true }` support so we
      // have to do it manually.
      if (flags.once) {
        emitter.removeEventListener(name, wrapListener);
      }
      listener(arg);
    });
  } else {
    throw new TypeError('The "emitter" argument must be of type EventEmitter. Received type ' + typeof emitter);
  }
}

},{}],53:[function(require,module,exports){
/*! ieee754. BSD-3-Clause License. Feross Aboukhadijeh <https://feross.org/opensource> */
exports.read = function (buffer, offset, isLE, mLen, nBytes) {
  var e, m
  var eLen = (nBytes * 8) - mLen - 1
  var eMax = (1 << eLen) - 1
  var eBias = eMax >> 1
  var nBits = -7
  var i = isLE ? (nBytes - 1) : 0
  var d = isLE ? -1 : 1
  var s = buffer[offset + i]

  i += d

  e = s & ((1 << (-nBits)) - 1)
  s >>= (-nBits)
  nBits += eLen
  for (; nBits > 0; e = (e * 256) + buffer[offset + i], i += d, nBits -= 8) {}

  m = e & ((1 << (-nBits)) - 1)
  e >>= (-nBits)
  nBits += mLen
  for (; nBits > 0; m = (m * 256) + buffer[offset + i], i += d, nBits -= 8) {}

  if (e === 0) {
    e = 1 - eBias
  } else if (e === eMax) {
    return m ? NaN : ((s ? -1 : 1) * Infinity)
  } else {
    m = m + Math.pow(2, mLen)
    e = e - eBias
  }
  return (s ? -1 : 1) * m * Math.pow(2, e - mLen)
}

exports.write = function (buffer, value, offset, isLE, mLen, nBytes) {
  var e, m, c
  var eLen = (nBytes * 8) - mLen - 1
  var eMax = (1 << eLen) - 1
  var eBias = eMax >> 1
  var rt = (mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0)
  var i = isLE ? 0 : (nBytes - 1)
  var d = isLE ? 1 : -1
  var s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0

  value = Math.abs(value)

  if (isNaN(value) || value === Infinity) {
    m = isNaN(value) ? 1 : 0
    e = eMax
  } else {
    e = Math.floor(Math.log(value) / Math.LN2)
    if (value * (c = Math.pow(2, -e)) < 1) {
      e--
      c *= 2
    }
    if (e + eBias >= 1) {
      value += rt / c
    } else {
      value += rt * Math.pow(2, 1 - eBias)
    }
    if (value * c >= 2) {
      e++
      c /= 2
    }

    if (e + eBias >= eMax) {
      m = 0
      e = eMax
    } else if (e + eBias >= 1) {
      m = ((value * c) - 1) * Math.pow(2, mLen)
      e = e + eBias
    } else {
      m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen)
      e = 0
    }
  }

  for (; mLen >= 8; buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8) {}

  e = (e << mLen) | m
  eLen += mLen
  for (; eLen > 0; buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8) {}

  buffer[offset + i - d] |= s * 128
}

},{}],54:[function(require,module,exports){
arguments[4][10][0].apply(exports,arguments)
},{"dup":10}],55:[function(require,module,exports){
/*!
 * Determine if an object is a Buffer
 *
 * @author   Feross Aboukhadijeh <https://feross.org>
 * @license  MIT
 */

// The _isBuffer check is for Safari 5-7 support, because it's missing
// Object.prototype.constructor. Remove this eventually
module.exports = function (obj) {
  return obj != null && (isBuffer(obj) || isSlowBuffer(obj) || !!obj._isBuffer)
}

function isBuffer (obj) {
  return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
}

// For Node v0.10 support. Remove this eventually.
function isSlowBuffer (obj) {
  return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isBuffer(obj.slice(0, 0))
}

},{}],56:[function(require,module,exports){
// shim for using process in browser
var process = module.exports = {};

// cached from whatever global is present so that test runners that stub it
// don't break things.  But we need to wrap it in a try catch in case it is
// wrapped in strict mode code which doesn't define any globals.  It's inside a
// function because try/catches deoptimize in certain engines.

var cachedSetTimeout;
var cachedClearTimeout;

function defaultSetTimout() {
    throw new Error('setTimeout has not been defined');
}
function defaultClearTimeout () {
    throw new Error('clearTimeout has not been defined');
}
(function () {
    try {
        if (typeof setTimeout === 'function') {
            cachedSetTimeout = setTimeout;
        } else {
            cachedSetTimeout = defaultSetTimout;
        }
    } catch (e) {
        cachedSetTimeout = defaultSetTimout;
    }
    try {
        if (typeof clearTimeout === 'function') {
            cachedClearTimeout = clearTimeout;
        } else {
            cachedClearTimeout = defaultClearTimeout;
        }
    } catch (e) {
        cachedClearTimeout = defaultClearTimeout;
    }
} ())
function runTimeout(fun) {
    if (cachedSetTimeout === setTimeout) {
        //normal enviroments in sane situations
        return setTimeout(fun, 0);
    }
    // if setTimeout wasn't available but was latter defined
    if ((cachedSetTimeout === defaultSetTimout || !cachedSetTimeout) && setTimeout) {
        cachedSetTimeout = setTimeout;
        return setTimeout(fun, 0);
    }
    try {
        // when when somebody has screwed with setTimeout but no I.E. maddness
        return cachedSetTimeout(fun, 0);
    } catch(e){
        try {
            // When we are in I.E. but the script has been evaled so I.E. doesn't trust the global object when called normally
            return cachedSetTimeout.call(null, fun, 0);
        } catch(e){
            // same as above but when it's a version of I.E. that must have the global object for 'this', hopfully our context correct otherwise it will throw a global error
            return cachedSetTimeout.call(this, fun, 0);
        }
    }


}
function runClearTimeout(marker) {
    if (cachedClearTimeout === clearTimeout) {
        //normal enviroments in sane situations
        return clearTimeout(marker);
    }
    // if clearTimeout wasn't available but was latter defined
    if ((cachedClearTimeout === defaultClearTimeout || !cachedClearTimeout) && clearTimeout) {
        cachedClearTimeout = clearTimeout;
        return clearTimeout(marker);
    }
    try {
        // when when somebody has screwed with setTimeout but no I.E. maddness
        return cachedClearTimeout(marker);
    } catch (e){
        try {
            // When we are in I.E. but the script has been evaled so I.E. doesn't  trust the global object when called normally
            return cachedClearTimeout.call(null, marker);
        } catch (e){
            // same as above but when it's a version of I.E. that must have the global object for 'this', hopfully our context correct otherwise it will throw a global error.
            // Some versions of I.E. have different rules for clearTimeout vs setTimeout
            return cachedClearTimeout.call(this, marker);
        }
    }



}
var queue = [];
var draining = false;
var currentQueue;
var queueIndex = -1;

function cleanUpNextTick() {
    if (!draining || !currentQueue) {
        return;
    }
    draining = false;
    if (currentQueue.length) {
        queue = currentQueue.concat(queue);
    } else {
        queueIndex = -1;
    }
    if (queue.length) {
        drainQueue();
    }
}

function drainQueue() {
    if (draining) {
        return;
    }
    var timeout = runTimeout(cleanUpNextTick);
    draining = true;

    var len = queue.length;
    while(len) {
        currentQueue = queue;
        queue = [];
        while (++queueIndex < len) {
            if (currentQueue) {
                currentQueue[queueIndex].run();
            }
        }
        queueIndex = -1;
        len = queue.length;
    }
    currentQueue = null;
    draining = false;
    runClearTimeout(timeout);
}

process.nextTick = function (fun) {
    var args = new Array(arguments.length - 1);
    if (arguments.length > 1) {
        for (var i = 1; i < arguments.length; i++) {
            args[i - 1] = arguments[i];
        }
    }
    queue.push(new Item(fun, args));
    if (queue.length === 1 && !draining) {
        runTimeout(drainQueue);
    }
};

// v8 likes predictible objects
function Item(fun, array) {
    this.fun = fun;
    this.array = array;
}
Item.prototype.run = function () {
    this.fun.apply(null, this.array);
};
process.title = 'browser';
process.browser = true;
process.env = {};
process.argv = [];
process.version = ''; // empty string to avoid regexp issues
process.versions = {};

function noop() {}

process.on = noop;
process.addListener = noop;
process.once = noop;
process.off = noop;
process.removeListener = noop;
process.removeAllListeners = noop;
process.emit = noop;
process.prependListener = noop;
process.prependOnceListener = noop;

process.listeners = function (name) { return [] }

process.binding = function (name) {
    throw new Error('process.binding is not supported');
};

process.cwd = function () { return '/' };
process.chdir = function (dir) {
    throw new Error('process.chdir is not supported');
};
process.umask = function() { return 0; };

},{}],57:[function(require,module,exports){
arguments[4][29][0].apply(exports,arguments)
},{"buffer":51,"dup":29}],58:[function(require,module,exports){
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

module.exports = Stream;

var EE = require('events').EventEmitter;
var inherits = require('inherits');

inherits(Stream, EE);
Stream.Readable = require('readable-stream/lib/_stream_readable.js');
Stream.Writable = require('readable-stream/lib/_stream_writable.js');
Stream.Duplex = require('readable-stream/lib/_stream_duplex.js');
Stream.Transform = require('readable-stream/lib/_stream_transform.js');
Stream.PassThrough = require('readable-stream/lib/_stream_passthrough.js');
Stream.finished = require('readable-stream/lib/internal/streams/end-of-stream.js')
Stream.pipeline = require('readable-stream/lib/internal/streams/pipeline.js')

// Backwards-compat with node 0.4.x
Stream.Stream = Stream;



// old-style streams.  Note that the pipe method (the only relevant
// part of this class) is overridden in the Readable class.

function Stream() {
  EE.call(this);
}

Stream.prototype.pipe = function(dest, options) {
  var source = this;

  function ondata(chunk) {
    if (dest.writable) {
      if (false === dest.write(chunk) && source.pause) {
        source.pause();
      }
    }
  }

  source.on('data', ondata);

  function ondrain() {
    if (source.readable && source.resume) {
      source.resume();
    }
  }

  dest.on('drain', ondrain);

  // If the 'end' option is not supplied, dest.end() will be called when
  // source gets the 'end' or 'close' events.  Only dest.end() once.
  if (!dest._isStdio && (!options || options.end !== false)) {
    source.on('end', onend);
    source.on('close', onclose);
  }

  var didOnEnd = false;
  function onend() {
    if (didOnEnd) return;
    didOnEnd = true;

    dest.end();
  }


  function onclose() {
    if (didOnEnd) return;
    didOnEnd = true;

    if (typeof dest.destroy === 'function') dest.destroy();
  }

  // don't leave dangling pipes when there are errors.
  function onerror(er) {
    cleanup();
    if (EE.listenerCount(this, 'error') === 0) {
      throw er; // Unhandled stream error in pipe.
    }
  }

  source.on('error', onerror);
  dest.on('error', onerror);

  // remove all the event listeners that were added.
  function cleanup() {
    source.removeListener('data', ondata);
    dest.removeListener('drain', ondrain);

    source.removeListener('end', onend);
    source.removeListener('close', onclose);

    source.removeListener('error', onerror);
    dest.removeListener('error', onerror);

    source.removeListener('end', cleanup);
    source.removeListener('close', cleanup);

    dest.removeListener('close', cleanup);
  }

  source.on('end', cleanup);
  source.on('close', cleanup);

  dest.on('close', cleanup);

  dest.emit('pipe', source);

  // Allow for unix-like usage: A.pipe(B).pipe(C)
  return dest;
};

},{"events":52,"inherits":54,"readable-stream/lib/_stream_duplex.js":60,"readable-stream/lib/_stream_passthrough.js":61,"readable-stream/lib/_stream_readable.js":62,"readable-stream/lib/_stream_transform.js":63,"readable-stream/lib/_stream_writable.js":64,"readable-stream/lib/internal/streams/end-of-stream.js":68,"readable-stream/lib/internal/streams/pipeline.js":70}],59:[function(require,module,exports){
arguments[4][13][0].apply(exports,arguments)
},{"dup":13}],60:[function(require,module,exports){
arguments[4][14][0].apply(exports,arguments)
},{"./_stream_readable":62,"./_stream_writable":64,"_process":56,"dup":14,"inherits":54}],61:[function(require,module,exports){
arguments[4][15][0].apply(exports,arguments)
},{"./_stream_transform":63,"dup":15,"inherits":54}],62:[function(require,module,exports){
arguments[4][16][0].apply(exports,arguments)
},{"../errors":59,"./_stream_duplex":60,"./internal/streams/async_iterator":65,"./internal/streams/buffer_list":66,"./internal/streams/destroy":67,"./internal/streams/from":69,"./internal/streams/state":71,"./internal/streams/stream":72,"_process":56,"buffer":51,"dup":16,"events":52,"inherits":54,"string_decoder/":73,"util":50}],63:[function(require,module,exports){
arguments[4][17][0].apply(exports,arguments)
},{"../errors":59,"./_stream_duplex":60,"dup":17,"inherits":54}],64:[function(require,module,exports){
arguments[4][18][0].apply(exports,arguments)
},{"../errors":59,"./_stream_duplex":60,"./internal/streams/destroy":67,"./internal/streams/state":71,"./internal/streams/stream":72,"_process":56,"buffer":51,"dup":18,"inherits":54,"util-deprecate":74}],65:[function(require,module,exports){
arguments[4][19][0].apply(exports,arguments)
},{"./end-of-stream":68,"_process":56,"dup":19}],66:[function(require,module,exports){
arguments[4][20][0].apply(exports,arguments)
},{"buffer":51,"dup":20,"util":50}],67:[function(require,module,exports){
arguments[4][21][0].apply(exports,arguments)
},{"_process":56,"dup":21}],68:[function(require,module,exports){
arguments[4][22][0].apply(exports,arguments)
},{"../../../errors":59,"dup":22}],69:[function(require,module,exports){
arguments[4][23][0].apply(exports,arguments)
},{"dup":23}],70:[function(require,module,exports){
arguments[4][24][0].apply(exports,arguments)
},{"../../../errors":59,"./end-of-stream":68,"dup":24}],71:[function(require,module,exports){
arguments[4][25][0].apply(exports,arguments)
},{"../../../errors":59,"dup":25}],72:[function(require,module,exports){
arguments[4][26][0].apply(exports,arguments)
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