code: public void setUserLedBlinking(final boolean USER_LED_BLINKING) {
          this.userLedBlinking = USER_LED_BLINKING;
          if (USER_LED_BLINKING) {
              USER_LED_BLINKING_TIMER.start();
          } else {
              setCurrentUserLedImage(getUserLedImageOff());
              USER_LED_BLINKING_TIMER.stop();
          }
      }
docs: Sets the state of the user led.
  The led could blink which will be triggered by a javax.swing.Timer
  that triggers every 500 ms. The blinking will be done by switching
  between two images.
  @param USER_LED_BLINKING