code: function (itemIndex) {
              // Don't do anything if the widget is disabled
              if (!this._data.disabled) {
                  var newVal = !this._data.items[itemIndex].selected;
                  this.setSelection(itemIndex, newVal);
                  return newVal;
              } else {
                  return this._data.items[itemIndex].selected;
              }
          }
docs: Toggles the selection of a specific item
  @param {Number} itemIndex Index of the item to toggle in the items array in the data model
  @return true if item is selected after this call, false if not selected