code: def _set_mult_grid_attr(self):
          
          grid_objs = self._get_grid_files()
  
          if self.grid_attrs is None:
              self.grid_attrs = {}
  
          # Override GRID_ATTRS with entries in grid_attrs
          attrs = internal_names.GRID_ATTRS.copy()
          for k, v in self.grid_attrs.items():
              if k not in attrs:
                  raise ValueError(
                      'Unrecognized internal name, {!r}, specified for a '
                      'custom grid attribute name.  See the full list of '
                      'valid internal names below:\n\n{}'.format(
                          k, list(internal_names.GRID_ATTRS.keys())))
              attrs[k] = (v, )
  
          for name_int, names_ext in attrs.items():
              for name in names_ext:
                  grid_attr = _get_grid_attr(grid_objs, name)
                  if grid_attr is not None:
                      TIME_STR = internal_names.TIME_STR
                      renamed_attr = _rename_coords(grid_attr, attrs)
                      if ((TIME_STR not in renamed_attr.dims) and
                         (TIME_STR in renamed_attr.coords)):
                          renamed_attr = renamed_attr.drop(TIME_STR)
                      setattr(self, name_int, renamed_attr)
                      break
docs: Set multiple attrs from grid file given their names in the grid file.