def test_bulk_response_external_id(self):
        conn1 = self.create_connection()
        conn2 = self.create_connection()
        config = {"sendsms_url": "http://example.com"}
        backend = VumiBackend(None, "vumi", **config)
        kwargs = backend.prepare_request("1234", "foo",
                                         [conn1.identity, conn2.identity],
                                         {'external_id': 'ASDF1234'})
        data = json.loads(kwargs['data'])
        self.assertTrue('in_reply_to' not in data)
Only single messages should include in_response_to.
dataset/ETHPy150Open rapidsms/rapidsms/rapidsms/backends/vumi/tests.py/VumiSendTest.test_bulk_response_external_id