How to use the @material/select/foundation.strings function in @material/select

notifyChange: value => {
          const index = this.selectedIndex;
          emitCustomEvent(
            this.$refs.root,
            MDCSelectFoundation.strings.CHANGE_EVENT,
            { value, index },
            true /* shouldBubble  */,
          );

          this.$emit('change', value);
        },

mounted() {
    const {
      SELECTED_ITEM_SELECTOR,
      SELECT_ANCHOR_SELECTOR,
      VALUE_ATTR,
    } = MDCSelectFoundation.strings;

    this.menuSetup_();

    this.foundation = new MDCSelectFoundation(
      Object.assign({
        // common methods
        addClass: className => this.$set(this.classes, className, true),
        removeClass: className => this.$delete(this.classes, className),
        hasClass: className => Boolean(this.classes[className]),

        setRippleCenter: normalizedX =>
          this.$refs.lineRippleEl &&
          this.$refs.lineRippleEl.setRippleCenter(normalizedX),
        activateBottomLine: () => {
          if (this.$refs.lineRippleEl) {
            this.$refs.lineRippleEl.foundation_.activate();

listElements.some((element: Element, elementIndex: number) => {
        if (
          element.getAttribute(
            MDCSelectFoundation.strings.ENHANCED_VALUE_ATTR
          ) === value
        ) {
          index = elementIndex;
          return true;
        }
        return false;
      });
    }

        el => el.getAttribute(MDCSelectFoundation.strings.VALUE_ATTR) || '',
      );