code: protected BufferedImage create_FOREGROUND_Image(final int WIDTH, final boolean WITH_CENTER_KNOB, final ForegroundType TYPE) {
          return create_FOREGROUND_Image(WIDTH, WITH_CENTER_KNOB, TYPE, null);
      }
docs: Returns the image of the selected (FG_TYPE1, FG_TYPE2, FG_TYPE3) glasseffect, the centered knob (if wanted)
  @param WIDTH
  @param WITH_CENTER_KNOB
  @param TYPE
  @return the foreground image that will be used