How to use the @material/checkbox/dist/mdc.checkbox.min.MDCCheckbox function in @material/checkbox

bind() {
		this.mdcCheckbox = new MDCCheckbox(this.element);
		this.element.id = '_' + this.id; // anders heeft dit element zelfde id als input. Raakt label for="" in de war
    }

bind() {
        this.mdcCheckbox = new MDCCheckbox(this.element);
        this.element.id = '_' + this.id;
    }

attached() {
        this.mdcCheckbox = new MDCCheckbox(this.element.firstElementChild);
        this.mdcCheckbox.required = this.required;
        this.mdcCheckbox.disabled = this.disabled;
        this.mdcCheckbox.indeterminate = this.indeterminate;

        if (!this.id) {
            this.id = this.unique;
        }
    }

_proto.attached = function attached() {
    this.mdcCheckbox = new _mdcCheckbox.MDCCheckbox(this.element.firstElementChild);
    this.mdcCheckbox.required = this.required;
    this.mdcCheckbox.disabled = this.disabled;
    this.mdcCheckbox.indeterminate = this.indeterminate;

    if (!this.id) {
      this.id = this.unique;
    }
  };

MdcCheckbox.prototype.bind = function bind() {
        this.mdcCheckbox = new _mdcCheckbox.MDCCheckbox(this.element);
        this.element.id = '_' + this.id;
    };