How to use the @material/select/dist/mdc.select.min.MDCSelect function in @material/select

attached() {
		this.myMdcSelect = new MDCSelect(this.element.firstElementChild);

		this.myMdcSelect.listen('change', () => {
			this.selected = this.myMdcSelect.value;

			//Set invalid class after first change
			if(!this.myMdcSelect.value && this.required) {
				this.requiredChanged(true);
			} else {
				this.requiredChanged(false);
			}
		});

		this.refreshOptions();
	}

_proto.attached = function attached() {
    var _this = this;

    this.myMdcSelect = new _mdcSelect.MDCSelect(this.element.firstElementChild);
    this.myMdcSelect.listen('change', function () {
      _this.changedEvent = true;
      _this.selected = _this.myMdcSelect.value; //Set invalid class after first change

      if (!_this.myMdcSelect.value && _this.required) {
        _this.requiredChanged(true);
      } else {
        _this.requiredChanged(false);
      }

      _this.changedEvent = false;
    });
    this.refreshOptions();
  };

attached() {
        this.myMdcSelect = new MDCSelect(this.element.firstElementChild);

        this.myMdcSelect.listen('change', () => {
            this.changedEvent = true;
            this.selected = this.myMdcSelect.value;

            //Set invalid class after first change
            if (!this.myMdcSelect.value && this.required) {
                this.requiredChanged(true);
            } else {
                this.requiredChanged(false);
            }

            this.changedEvent = false;
        });

        this.refreshOptions();

bind() {
		this.myMdcSelect = new MDCSelect(this.element);
		this.myMdcSelect.disabled = this.disabled;

		if (this.selected) {
			this.addFloatingLabel();
		}
	}

MdcSelect.prototype.bind = function bind() {
		this.myMdcSelect = new _mdcSelect.MDCSelect(this.element);
		this.myMdcSelect.disabled = this.disabled;

		if (this.selected) {
			this.addFloatingLabel();
		}
	};