@patch('compass.hdsdiscovery.utils.ssh_remote_execute')
    def test_scan(self, ovs_mock):
        ovs_mock.return_value = []
        mac_instance = OVSMac(self.host, self.credential)
        self.assertIsNone(mac_instance.scan())
        del mac_instance

        ovs_mock.return_value = ['\n', '\n', '\n']
        mac_instance = OVSMac(self.host, self.credential)
        self.assertEqual([], mac_instance.scan())
        del mac_instance
If an ``X-If-Configuration-Matches`` header is sent with a matching
dataset/ETHPy150Open openstack/compass-core/compass/tests/hdsdiscovery/test_hdsdiscovery.py/OVSMacTest.test_scan--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/flocker/control/test/test_httpapi.py/UpdatePrimaryDatasetTestsMixin.test_if_matches_success