    @Test
    public void test_flushTopicConfig() throws Exception {

        BrokerController brokerController = new BrokerController(//
            new BrokerConfig(), //
            new NettyServerConfig(), //
            new NettyClientConfig(), //
            new MessageStoreConfig());
        boolean initResult = brokerController.initialize();
        System.out.println("initialize " + initResult);
        brokerController.start();

        TopicConfigManager topicConfigManager = new TopicConfigManager(brokerController);

        TopicConfig topicConfig =
                topicConfigManager.createTopicInSendMessageMethod("TestTopic_SEND", MixAll.DEFAULT_TOPIC,
                    null, 4, 0);
        assertTrue(topicConfig != null);

        System.out.println(topicConfig);

        for (int i = 0; i < 10; i++) {
            String topic = "UNITTEST-" + i;
            topicConfig =
                    topicConfigManager
                        .createTopicInSendMessageMethod(topic, MixAll.DEFAULT_TOPIC, null, 4, 0);
            assertTrue(topicConfig != null);
        }

        topicConfigManager.persist();

        brokerController.shutdown();
    }