How to use the @material/menu.MDCMenuFoundation.strings function in @material/menu

      notifySelected: (evtData) => this.emit(MDCMenuFoundation.strings.SELECTED_EVENT, {
        index: evtData.index,
        item: angular.element(this.items[evtData.index]).controller(MDCMenuItemController.name),
      }),
      notifyCancel: () => this.emit(MDCMenuFoundation.strings.CANCEL_EVENT, {}),

      notifyCancel: () => this.emit(MDCMenuFoundation.strings.CANCEL_EVENT, {}),
      saveFocus: () => {

$onDestroy() {
    this.mdcMenuController.unlisten(MDCMenuFoundation.strings.SELECTED_EVENT, this.selectHandler);
    this.mdcMenuController.removeItem_(this);
  }

setupMenu_(menu) {
    this.menuParent_ = this.tabBar.scroller ? this.tabBar.scroller.$element : this.tabBar.$element;
    menu.$element.detach();
    this.menuParent_.after(menu.$element);

    menu.listen(MDCMenuFoundation.strings.SELECTED_EVENT, ({detail: {item}}) => {
      if (this.tabBar.ngModel) {
        this.tabBar.value = item.getValue();
      } else {
        this.tabBar.activateTab(this);
      }
    });
  }

get itemsContainer_() {
    return this.root_.querySelector(MDCMenuFoundation.strings.ITEMS_SELECTOR);
  }