_addScrollBar() {
    const canvas = this.getCanvas();

    canvas.add(this._horizontalScroll);
    canvas.add(this._verticalScroll);

    if (this.scrollBarTid) {
      clearTimeout(this.scrollBarTid);
    }

    this.scrollBarTid = setTimeout(() => {
      canvas.remove(this._horizontalScroll);
      canvas.remove(this._verticalScroll);
    }, 3000);
  }
Add scroll bar and set remove timer