@Override
 public Float get(RevealAnimator object) {
   return object.getRevealRadius();
 }
 @Override
 public void onAnimationStart(Animator animation) {
   RevealAnimator target = mReference.get();
   target.onRevealAnimationStart();
 }
 @Override
 public void setValue(RevealAnimator object, float value) {
   object.setRevealRadius(value);
 }