@Override
    public int deleteTopics(Set<String> deleteTopics) {
        for (String topic : deleteTopics) {
            metadataStore.iterateQueue(topic, queueMetadata -> {
                flatFileStore.destroyFile(queueMetadata.getQueue());
            });
            metadataStore.deleteTopic(topic);
            log.info("MessageStore delete topic success, topicName={}", topic);
        }
        return next.deleteTopics(deleteTopics);
    }
@Test
    public void testDeleteTopics() {
        Set<String> topicSet = new HashSet<>();
        topicSet.add(mq.getTopic());
        currentStore.deleteTopics(topicSet);
        Assert.assertNull(flatFileStore.getFlatFile(mq));
        Assert.assertNull(flatFileStore.getMetadataStore().getTopic(mq.getTopic()));
        Assert.assertNull(flatFileStore.getMetadataStore().getQueue(mq));
    }