public void startListener() {
            try {
                if (start.compareAndSet(false, true)) {
                    nodeCache.start(true);
                    nodeCache.getListenable().addListener(nodeCacheListener);
                }
            } catch (Exception e) {
                throw new ZkException(e);
            }
        }
@author Robert HG (254963746@qq.com) on 5/16/15.
lts-core/src/main/java/com/github/ltsopensource/zookeeper/curator/CuratorZkClient.java