How to use the @material/floating-label/foundation function in @material/floating-label

mounted() {
    this.foundation = new MDCFloatingLabelFoundation({
      addClass: className => {
        this.$set(this.labelClasses, className, true);
      },
      removeClass: className => {
        this.$delete(this.labelClasses, className);
      },
      getWidth: () => this.$el.scrollWidth,
      registerInteractionHandler: (evtType, handler) => {
        this.$el.addEventListener(evtType, handler);
      },
      deregisterInteractionHandler: (evtType, handler) => {
        this.$el.removeEventListener(evtType, handler);
      },
    });
    this.foundation.init();
  },

mounted() {
    this.foundation = new MDCFloatingLabelFoundation({
      addClass: className => {
        this.$set(this.labelClasses, className, true);
      },
      removeClass: className => {
        this.$delete(this.labelClasses, className);
      },
      getWidth: () => this.$el.scrollWidth,
      registerInteractionHandler: (evtType, handler) => {
        this.$el.addEventListener(evtType, handler);
      },
      deregisterInteractionHandler: (evtType, handler) => {
        this.$el.removeEventListener(evtType, handler);
      },
    });
    this.foundation.init();
  },