def _containers_test(self, deployment, expected):
        saving = self.persistence_service.save(deployment)

        def saved(ignored):
            return self.assertResultItems(
                b"GET", b"/configuration/containers", None, OK, expected
            )
        saving.addCallback(saved)
        return saving
Verify that when the control service has ``deployment``
dataset/ETHPy150Open ClusterHQ/flocker/flocker/control/test/test_httpapi.py/GetContainerConfigurationTestsMixin._containers_test