public void registerListenerFirst(ZooKeeperListener listener) {
        listeners.add(0, listener);
    }
Register the specified listener to receive ZooKeeper events and add it as the first in the
list of current listeners.
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/common/zookeeper/ZooKeeperWatcher.java