code: def reduce(self, func, dim=None, keep_attrs=None, **kwargs):
          
          if dim == DEFAULT_DIMS:
              dim = None
  
          return super(DatasetResample, self).reduce(
              func, dim, keep_attrs, **kwargs)
docs: Reduce the items in this group by applying `func` along the
          pre-defined resampling dimension.
  
          Parameters
          ----------
          func : function
              Function which can be called in the form
              `func(x, axis=axis, **kwargs)` to return the result of collapsing
              an np.ndarray over an integer valued axis.
          dim : str or sequence of str, optional
              Dimension(s) over which to apply `func`.
          keep_attrs : bool, optional
              If True, the datasets's attributes (`attrs`) will be copied from
              the original object to the new one.  If False (default), the new
              object will be returned without attributes.
          **kwargs : dict
              Additional keyword arguments passed on to `func`.
  
          Returns
          -------
          reduced : Array
              Array with summarized data and the indicated dimension(s)
              removed.