code: function (statusText) {
              var self = this;
              statusText = statusText || 'abort';
              if (self.transport) {
                  self.transport.abort(statusText);
              }
              self._ioReady(0, statusText);
              return self;
          }
docs: cancel this request
  @member KISSY.IO
  @param {String} [statusText=abort] error reason as current request object's statusText
  @chainable