title: Presenting a modal view controller only after another one has been dismissed
body: <p>I can't just do</p>
  
  <pre><code>[myViewController dismissModalViewControllerAnimated:YES];
  [myViewController presentModalViewController:nextModalViewController animated:YES];
  </code></pre>
  
  <p>one after the other, because then the two animation blocks try to affect the same references simultaneously and things break badly.</p>
  
  <p>So what I need to do is make the latter call only after the first animation has finished. But there's no <code>UIViewControllerDelegate</code> method like <code>didDismissModalViewController</code>. What should I do?</p>