code: function Register(client, path) {
    if (!(this instanceof Register)) return new Register(client);
    EventEmitter.call(this);
    this._client = client;
    this._path = path;
    // Register status. Supported 'unwatched' / 'pending' / 'watched'.
    this._status = 'unwatched';
  
    this._watcher = this._watcher.bind(this);
  }
docs: Constructor of Register.
  
  @param client // The Client instance of zookeeper.
  @param path // The path of zookeeper node.
  @returns {Register}
  @constructor