def METHOD_NAME(self, group_id):
    self._logger.info("Remove group %s" % group_id)
    members = self.get_group_members(group_id)
    if members is not None:
        for ref in members:
            self._file_to_groups[ref].remove(group_id)
            if not self._file_to_groups[ref]:
                self.add_to_group(DEFAULT_GROUP, ref)
        del self._group_dict[group_id]