public class Solution {
    public static void main(String[] args) {
        try {
            RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
            CuratorFramework curatorFramework = CuratorFrameworkFactory.builder()
            .connectString("127.0.0.1:2181")
            .sessionTimeoutMs(50000)
            .connectionTimeoutMs(30000)
            .retryPolicy(retryPolicy)
            .namespace("servers")
            .build();
            curatorFramework.start();
            CuratorCache curatorCache = CuratorCache.builder(curatorFramework, "/").build(); // ①
            CuratorCacheListener curatorCacheListener = CuratorCacheListener.builder().forPathChildrenCache("/", curatorFramework, new PathChildrenCacheListener() { // ②
                @Override
                public void childEvent(CuratorFramework curatorFramework, PathChildrenCacheEvent pathChildrenCacheEvent) throws Exception {
                    // ... 
                }
            }).build();
            curatorCache.listenable().addListener(curatorCacheListener);
            curatorCache.start();
            Thread.sleep(Integer.MAX_VALUE);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

代码 ① 处需设置 path，代码 ② 处同样需要设置 path，这两处的 path 分别代表什么意思呢？