default int getPreferredSpace() {
      Icon icon1 = getIcon(true);
      Icon icon2 = getIcon(false);
      if (icon1 == null && icon2 == null) return 0;
      if (icon1 == null) return getIconGap() + icon2.getIconWidth();
      if (icon2 == null) return getIconGap() + icon1.getIconWidth();
      return getIconGap() + Math.max(icon1.getIconWidth(), icon2.getIconWidth());
    }
default int getPreferredSpace()