@Override
    public void close() throws IOException {
        httpclient.close();
    }
Adding topic is an async operation, so this method should
1. check whether pendingTopic contains topic that has failed/succeeded to be added.
2. async add topic to tubemq cluster

@param brokerInfoList - broker list
@param pendingTopic - topicMap
inlong-tubemq/tubemq-manager/src/main/java/org/apache/inlong/tubemq/manager/service/NodeServiceImpl.java