Store the async result instance of a taskset.

        :param taskset_id: task set id

        :param result: The return value of the taskset

def store_result(self, taskset_id, result):
        """Store the async result instance of a taskset.

        :param taskset_id: task set id

        :param result: The return value of the taskset

        """
        return self.update_or_create(taskset_id=taskset_id,
                                     defaults={'result': result})