public static String clientTagPrefix(final String clientTagKey) {
        return CLIENT_TAG_PREFIX + clientTagKey;
    }
@Test
    public void shouldSetRackAwareAssignmentTags() {
        props.put(StreamsConfig.clientTagPrefix("cluster"), "cluster-1");
        props.put(StreamsConfig.clientTagPrefix("zone"), "eu-central-1a");
        props.put(StreamsConfig.RACK_AWARE_ASSIGNMENT_TAGS_CONFIG, "cluster,zone");
        final StreamsConfig config = new StreamsConfig(props);
        assertEquals(new HashSet<>(config.getList(StreamsConfig.RACK_AWARE_ASSIGNMENT_TAGS_CONFIG)),
                     mkSet("cluster", "zone"));
    }