code: function (batch, xhr) {
                  for (var i = 0, requestId; i < batch.length; i++) {
                      requestId = this._getRequestId(batch[i].method, batch[i].params);
                      this._rejectPromise(this._deferreds[requestId], xhr);
                      delete this._deferreds[requestId];
                  }
              }
docs: Rejects deferred promises.
  
  @param {Object[]} batch Batch request data.
  @param {XMLHttpRequest} xhr