public RemotingCommand cleanUnusedTopic() {
        LOGGER.warn("invoke cleanUnusedTopic start.");
        final RemotingCommand response = RemotingCommand.createResponseCommand(null);
        brokerController.getMessageStore().cleanUnusedTopic(brokerController.getTopicConfigManager().getTopicConfigTable().keySet());
        LOGGER.warn("invoke cleanUnusedTopic end.");
        response.setCode(ResponseCode.SUCCESS);
        response.setRemark(null);
        return response;
    }
@Test
    public void testCleanUnusedTopic() throws RemotingCommandException {
        RemotingCommand request = RemotingCommand.createRequestCommand(RequestCode.CLEAN_UNUSED_TOPIC, null);
        RemotingCommand response = adminBrokerProcessor.processRequest(handlerContext, request);
        assertThat(response.getCode()).isEqualTo(ResponseCode.SUCCESS);
    }