creds = 
def test_resume_publish(creds):
    publisher_options = types.PublisherOptions(enable_message_ordering=True)
    client = publisher.Client(publisher_options=publisher_options, credentials=creds)

    topic = "topic"
    ordering_key = "ord_key"
    sequencer = mock.Mock(spec=ordered_sequencer.OrderedSequencer)
    client._set_sequencer(topic=topic, sequencer=sequencer, ordering_key=ordering_key)

    client.resume_publish(topic, ordering_key)


  assert sequencer.unpause.called_once()


tests/unit/pubsub_v1/publisher/test_publisher_client.py:639:

self = , name = 'called_once'
def __getattr__(self, name):
    if name in {'_mock_methods', '_mock_unsafe'}:
        raise AttributeError(name)
    elif self._mock_methods is not None:
        if name not in self._mock_methods or name in _all_magics:
            raise AttributeError("Mock object has no attribute %r" % name)
    elif _is_magic(name):
        raise AttributeError(name)
    if not self._mock_unsafe and (not self._mock_methods or name not in self._mock_methods):
        if name.startswith(('assert', 'assret', 'asert', 'aseert', 'assrt')) or name in _ATTRIB_DENY_LIST:
            raise AttributeError(


              f"{name!r} is not a valid assertion. Use a spec "


                f"for the mock if {name!r} is meant to be an attribute.")

E               AttributeError: 'called_once' is not a valid assertion. Use a spec for the mock if 'called_once' is meant to be an attribute.
.nox/unit-3-7/lib/python3.7/site-packages/mock/mock.py:661: AttributeError