docs: function () {
  
              var waiAria = this._cfg.waiAria;
              this.navigationInterceptor = DomNavigationManager.ModalNavigationHandler(this._dropdownPopup.domElement, !waiAria);
              this.navigationInterceptor.ensureElements();
  
              this._setPopupOpenProperty(true);
              // when the popup is clicked, don't give it focus, allow focus to be passed to the List in _refreshPopup
              this._keepFocus = true;
              var list = this.controller.getListWidget();
              this._dropDownOpen = true;
              this._focusMultiSelect(list);
              if (waiAria) {
                  var dropDownIcon = this._getDropdownIcon();
                  if (dropDownIcon) {
                      dropDownIcon.setAttribute("aria-expanded", "true");
                  }
              }
          }