code: @Test public void testChildrenListener() throws InterruptedException {
    String path="/dubbo/org.apache.dubbo.demo.DemoService/providers";
    curatorClient.create(path,false);
    final CountDownLatch countDownLatch=new CountDownLatch(1);
    curatorClient.addTargetChildListener(path,new CuratorWatcher(){
      @Override public void process(    WatchedEvent watchedEvent) throws Exception {
        countDownLatch.countDown();
      }
    }
  );
    curatorClient.createPersistent(path + "/provider1");
    countDownLatch.await();
  }
  