@Override
    public List<InetSocketAddress> lookup(String key) throws Exception {
        final String cluster = getServiceGroup(key);
        if (cluster == null) {
            String missingDataId = PREFIX_SERVICE_ROOT + CONFIG_SPLIT_CHAR + PREFIX_SERVICE_MAPPING + key;
            throw new ConfigNotFoundException("%s configuration item is required", missingDataId);
        }
        return lookupByCluster(cluster);

    }
@Test
    public void testLookup() throws Exception {
        RegistryService registryService = mock(ConsulRegistryServiceImpl.class);
        registryService.lookup("test-key");
        verify(registryService).lookup("test-key");
    }