def test_docker_client_default(self):
        self.assertIsInstance(
            ApplicationNodeDeployer(u"example.com", None).docker_client,
            DockerClient
        )
``ApplicationNodeDeployer.docker_client`` is a ``DockerClient`` by
dataset/ETHPy150Open ClusterHQ/flocker/flocker/node/test/test_container.py/ApplicationNodeDeployerAttributesTests.test_docker_client_default