public static RecoverableZooKeeper connect(Configuration conf, Watcher watcher)
    throws IOException {
    String ensemble = ZKConfig.getZKQuorumServersString(conf);
    return connect(conf, ensemble, watcher, null, null);
  }
See {@link #connect(Configuration, String, Watcher, String, ZKClientConfig)}.
hbase-zookeeper/src/main/java/org/apache/hadoop/hbase/zookeeper/RecoverableZooKeeper.java