docs: function (ioRes) {
              var downloadFailed = (ioRes.status != '200');
              if (downloadFailed) {
                  this.$logError(this.DESCRIPTOR_NOT_LOADED, this._customizationDescriptor);
              } else {
                  var resJson = ariaUtilsJson.load(ioRes.responseText);
                  if (resJson == null) {
                      // the descriptor was not valid json
                      this.$logError(this.INVALID_DESCRIPTOR, this._customizationDescriptor);
                      this.$raiseEvent("descriptorLoaded");
                      return;
                  }
  
                  this._setCustomizationDescriptor(resJson);
              }
  
              this._descriptorLoaded = true;
              this.$raiseEvent("descriptorLoaded");
          }