docs: def _get_coord_cell_node_coord(self, coord, coords=None, nans=None,
                                     var=None):
          """
          Get the boundaries of an unstructed coordinate
  
          Parameters
          ----------
          coord: xr.Variable
              The coordinate whose bounds should be returned
          %(CFDecoder.get_cell_node_coord.parameters.no_var|axis)s
  
          Returns
          -------
          %(CFDecoder.get_cell_node_coord.returns)s
          """
          bounds = coord.attrs.get('bounds')
          if bounds is not None:
              bounds = self.ds.coords.get(bounds)
          if bounds is not None:
              if coords is not None:
                  bounds = bounds.sel(**{
                      key: coords[key]
                      for key in set(coords).intersection(bounds.dims)})
              if nans is not None and var is None:
                  raise ValueError("Need the variable to deal with NaN!")
              elif nans is None:
                  pass
              elif nans == 'skip':
                  bounds = bounds[~np.isnan(var.values)]
              elif nans == 'only':
                  bounds = bounds[np.isnan(var.values)]
              else:
                  raise ValueError(
                      "`nans` must be either None, 'skip', or 'only'! "
                      "Not {0}!".format(str(nans)))
              return bounds