public NewTopic configs(Map<String, String> configs) {
        this.configs = configs;
        return this;
    }
@Test
    public void testConfigsNotNull() {
        NewTopic newTopic = new NewTopic(TEST_TOPIC, NUM_PARTITIONS, REPLICATION_FACTOR);
        Map<String, String> configs = new HashMap<>();
        configs.put(CLEANUP_POLICY_CONFIG_KEY, CLEANUP_POLICY_CONFIG_VALUE);
        newTopic.configs(configs);
        assertEquals(configs, newTopic.configs());
    }