__getIncrementButtonNode() {
    const renderParent = document.createElement('div');
    render(
      this._incrementorTemplate(),
      renderParent,
      /** @type {RenderOptions} */ ({
        scopeName: this.localName,
        eventContext: this,
      }),
    );
    return renderParent.firstElementChild;
  }
Get the increment button node
@returns {Element|null}
@private