code: protected BufferedImage create_GLOW_Image(final int WIDTH, final int HEIGHT, final Color GLOW_COLOR, final boolean ON) {
          return GLOW_FACTORY.createLinearGlow(WIDTH, HEIGHT, GLOW_COLOR, ON);
      }
docs: Returns an image that simulates a glowing ring which could be used to visualize
  a state of the gauge by a color. The LED might be too small if you are not in front
  of the screen and so one could see the current state more easy.
  @param WIDTH
  @param HEIGHT
  @param GLOW_COLOR
  @param ON
  @return an image that simulates a glowing ring