code: function (optionIndex) {
              if (this._subTplCtxt) {
                  var data = this._subTplModuleCtrl.getData();
                  if (data.waiAria && optionIndex > -1 && optionIndex < data.items.length) {
                      return this._subTplCtxt.$getId(data.listItemDomIdPrefix + optionIndex);
                  }
              }
          }
docs: Returns the id of the DOM element corresponding to the item in the list at the given index.
  This method only works if accessibility was enabled at the time the list widget was created.
  @param {Integer} optionIndex index of the item whose id should be returned
  @return {String} id of the DOM element or undefined if the list is not fully loaded yet, accessibility
  is disabled or the index is invalid