asset.createFromFiles doesn't work properly with plainObjects (or I couldn't figure it out)

[3aluw]

I tried the same example shown here but using the planiObject API:

scopedPlainClient.asset.createFromFiles(
{environmentId:"master"},
{
   fields: {
    title: {
      'en-US': 'Asset title'
    },
    description: {
      'en-US': 'Asset description'
    },
    file: {
      'en-US': {
        contentType: 'image/svg+xml',
        fileName: 'circle.svg',
        file: '<svg><path fill="red" d="M50 50h150v50H50z"/></svg>'
      }
    }
  }
})

but the svg doesn't get processed on contentful and it keep saying loading.

So is this a bug. or am I doing something wrong ?