code: public static CmsFadeAnimation fadeOut(Element element, Command callback, int duration) {
  
          CmsFadeAnimation animation = new CmsFadeAnimation(element, false, callback);
          animation.run(duration);
          return animation;
      }
docs: Fades the given element out of view executing the callback afterwards.<p>
  
  @param element the element to fade out
  @param callback the callback
  @param duration the animation duration
  
  @return the running animation object