def test_close():
        (
            manager,
            consumer,
            dispatcher,
            leaser,
            heartbeater,
            scheduler,
        ) = make_running_manager()
    manager.close()

    consumer.stop.assert_called_once()
    leaser.stop.assert_called_once()
    dispatcher.stop.assert_called_once()


  heartbeater.stop.assert_called_once()


tests/unit/pubsub_v1/subscriber/test_streaming_pull_manager.py:568:

_mock_self = 
def assert_called_once(_mock_self):
    """assert that the mock was called only once.
    """
    self = _mock_self
    if not self.call_count == 1:
        msg = ("Expected '%s' to have been called once. Called %s times.%s"
               % (self._mock_name or 'mock',
                  self.call_count,
                  self._calls_repr()))


      raise AssertionError(msg)


E           AssertionError: Expected 'stop' to have been called once. Called 0 times.
.nox/unit-3-9/lib/python3.9/site-packages/mock/mock.py:891: AssertionError