esmlab.resample fails when method chaining is used

[andersy005]

esmlab.resample(esmlab.resample(dset(), freq='mon'), freq='mon')

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-48-fef802d43a24> in <module>
----> 1 esmlab.resample(esmlab.resample(dset(), freq='mon'), freq='mon')

/gpfs/u/home/mclong/codes/esmlab/esmlab/core.py in resample(dset, freq, weights, time_coord_name, method)
    774 
    775     if freq == 'mon':
--> 776         ds = dset.esmlab.set_time(time_coord_name=time_coord_name).compute_mon_mean(method=method)
    777 
    778     else:

/gpfs/u/home/mclong/codes/esmlab/esmlab/core.py in set_time(self, time_coord_name, year_offset)
    346                     print('Please open dataset with `decode_times=False`')
    347                     raise exc
--> 348         self.setup()
    349         return self
    350 

/gpfs/u/home/mclong/codes/esmlab/esmlab/core.py in setup(self)
    351     def setup(self):
    352         self.get_variables()
--> 353         self.compute_time()
    354         self.get_original_metadata()
    355 

/gpfs/u/home/mclong/codes/esmlab/esmlab/core.py in compute_time(self)
     80 
     81         if self.time_bound is not None:
---> 82             groupby_coord = self.get_time_decoded(midpoint=True)
     83 
     84         else:

/gpfs/u/home/mclong/codes/esmlab/esmlab/core.py in get_time_decoded(self, midpoint)
    184                 units=self.time_attrs['units'],
    185                 calendar=self.time_attrs['calendar'],
--> 186                 only_use_cftime_datetimes=True,
    187             )
    188         )

/glade/work/mclong/miniconda3/envs/dev/lib/python3.7/site-packages/xarray/core/common.py in __setattr__(self, name, value)
    191                     "style assignment (e.g., `ds['name'] = ...`) instead to "
    192                     "assign variables." % (name, type(self).__name__))
--> 193         object.__setattr__(self, name, value)
    194 
    195     def __dir__(self):

/glade/work/mclong/miniconda3/envs/dev/lib/python3.7/site-packages/xarray/core/dataarray.py in data(self, value)
    403     @data.setter
    404     def data(self, value):
--> 405         self.variable.data = value
    406 
    407     @property

/glade/work/mclong/miniconda3/envs/dev/lib/python3.7/site-packages/xarray/core/variable.py in data(self, data)
   1832     @Variable.data.setter  # type: ignore
   1833     def data(self, data):
-> 1834         Variable.data.fset(self, data)
   1835         if not isinstance(self._data, PandasIndexAdapter):
   1836             self._data = PandasIndexAdapter(self._data)

/glade/work/mclong/miniconda3/envs/dev/lib/python3.7/site-packages/xarray/core/variable.py in data(self, data)
    302         if data.shape != self.shape:
    303             raise ValueError(
--> 304                 "replacement data must match the Variable's shape")
    305         self._data = data
    306 

ValueError: replacement data must match the Variable's shape