code: public void showMenu (Stage stage, Actor actor) {
  		Vector2 pos = actor.localToStageCoordinates(tmpVector.setZero());
  		float menuY;
  		if (pos.y - getHeight() <= 0) {
  			menuY = pos.y + actor.getHeight() + getHeight() - sizes.borderSize;
  		} else {
  			menuY = pos.y + sizes.borderSize;
  		}
  		showMenu(stage, pos.x, menuY);
  	}
docs: Shows menu below (or above if not enough space) given actor.
  @param stage stage instance that this menu is being added to
  @param actor used to get calculate menu position in stage, menu will be displayed above or below it