code: public void fade (int duration, float endVolume, boolean stopAfterFade) {
  		this.stopAfterFade = stopAfterFade;
  		fadeStartGain = volume;
  		fadeEndGain = endVolume;
  		fadeDuration = duration;
  		fadeTime = duration;
  	}
docs: Fade this music to the volume specified
  
  @param duration Fade time in milliseconds.
  @param endVolume The target volume
  @param stopAfterFade True if music should be stopped after fading in/out