Touch all of the related models of the relationship.

def touch(self):
        """
        Touch all of the related models of the relationship.
        """
        key = self.get_related().get_key_name()

        columns = self.get_related_fresh_update()

        ids = self.get_related_ids()

        if len(ids) > 0:
            self.get_related().new_query().where_in(key, ids).update(columns)