def _fill(self, direction, limit=None):
res = super()._fill(direction, limit=limit)<EOL>output = OrderedDict(<EOL>(grp.name, grp.grouper) for grp in self.grouper.groupings)<EOL>from pandas import concat<EOL>return concat((self._wrap_transformed_output(output), res), axis=<NUM_LIT:1>)<EOL>
Overridden method to join grouped columns in output