docs: function (_callback)
      {
          Strophe.error("Server did not send any auth methods");
          this._conn._changeConnectStatus(Strophe.Status.CONNFAIL, "Server did not send any auth methods");
          if (_callback) {
              _callback = _callback.bind(this._conn);
              _callback();
          }
          this._conn._doDisconnect();
      }