docs: function (newlySelectedIndexes, newlyUnselectedIndexes) {
              var data = this._data;
              if (newlySelectedIndexes.length === 0 && data.selectedCount === 0) {
                  var preselect = this._checkPreselect();
                  if (preselect != null) {
                      newlySelectedIndexes = [preselect];
                      this.json.setValue(data.itemsView.items[preselect].value, "selected", true);
                      this.json.setValue(data, "selectedIndex", preselect);
                      this.json.setValue(data, "selectedCount", 1);
                  }
              }
  
              this.$raiseEvent({
                  name : "onChange",
                  selectedIndexes : newlySelectedIndexes,
                  unselectedIndexes : newlyUnselectedIndexes
              });
          }