code: def _maybe_cast_to_float64(da):
      
      if da.dtype == np.float32:
          logging.warning('Datapoints were stored using the np.float32 datatype.'
                          'For accurate reduction operations using bottleneck, '
                          'datapoints are being cast to the np.float64 datatype.'
                          ' For more information see: https://github.com/pydata/'
                          'xarray/issues/1346')
          return da.astype(np.float64)
      else:
          return da
docs: Cast DataArrays to np.float64 if they are of type np.float32.
  
      Parameters
      ----------
      da : xr.DataArray
          Input DataArray
  
      Returns
      -------
      DataArray