title: What are Unwind segues for and how do you use them?
body: <p>iOS 6 and Xcode 4.5 has a new feature referred to as "Unwind Segue":</p>
  
  <blockquote>
    <p>Unwind segues can allow transitioning to existing instances of scenes in a storyboard</p>
  </blockquote>
  
  <p>In addition to this brief entry in Xcode 4.5's release notes, UIViewController now seem to have a couple of new methods:</p>
  
  <pre><code>- (BOOL)canPerformUnwindSegueAction:(SEL)action fromViewController:(UIViewController *)fromViewController withSender:(id)sender
  - (UIViewController *)viewControllerForUnwindSegueAction:(SEL)action fromViewController:(UIViewController *)fromViewController withSender:(id)sender
  - (UIStoryboardSegue *)segueForUnwindingToViewController:(UIViewController *)toViewController fromViewController:(UIViewController *)fromViewController identifier:(NSString *)identifier
  </code></pre>
  
  <p>How do unwind segues work and what they can be used for?</p>