Given a list of set, combine them to create the final set that will be
        used to make the final redis call.

def _combine_sets(self, sets, final_set):
        """
        Given a list of set, combine them to create the final set that will be
        used to make the final redis call.
        """
        self.cls.get_connection().sinterstore(final_set, list(sets))
        return final_set