code: function positionScrollButtons() {
  		this._topScrollButton.style.width = this._dropdownNode.clientWidth + 1 + "px";
  		this._bottomScrollButton.style.width = this._dropdownNode.clientWidth + 1 + "px";
  		this._topScrollButton.style.top = this._dropdownNode.style.top;
  		this._topScrollButton.style.left = this._topScrollButton.parentNode.clientWidth + "px";
  		this._bottomScrollButton.style.top = Number(this._dropdownNode.style.top.replace("px", "")) + (this._dropdownNode.clientHeight-this._bottomScrollButton.clientHeight + 1)+"px";
  		this._bottomScrollButton.style.left = this._bottomScrollButton.parentNode.clientWidth + "px";
  	}
docs: Positions the top and bottom scroll buttons according to where the dropdown list is positioned