title: iPhone - Catching the end of a grouped animation
body: <p>I animate 2 views, each one with its CAAnimationGroup that contains 2 CAAnimations. They are launched at the same time (if computing time is negligible), and have the same duration.</p>
  
  <p>How may I do to know when both grouped animation is finished.  </p>
  
  <p>I put the <code>- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag</code> delegate method, but... What may I test ? Sounds simple, but I don't see the way of doing this.</p>