/**
  * The color with which the background will be drawn.
  *
  * @return int representation of a rgba string color
  * @throws RuntimeException thrown if property isn't a value
  */
 @ColorInt
 public int getBackgroundColorAsInt() {
   PropertyValue<String> value = getBackgroundColor();
   if (value.isValue()) {
     return rgbaToColor(value.getValue());
   } else {
     throw new RuntimeException("background-color was set as a Function");
   }
 }