code: def from_series(cls, series):
          
          # TODO: add a 'name' parameter
          name = series.name
          df = pd.DataFrame({name: series})
          ds = Dataset.from_dataframe(df)
          return ds[name]
docs: Convert a pandas.Series into an xarray.DataArray.
  
          If the series's index is a MultiIndex, it will be expanded into a
          tensor product of one-dimensional coordinates (filling in missing
          values with NaN). Thus this operation should be the inverse of the
          `to_series` method.