title: How to send message to a parentViewController that is a subclass of UIViewController?
body: <p>I have a UIViewController (MyViewController) and another view controller i'm presenting modally though MyViewController (call it SecondViewController).  I want to be able to send a message to MyViewController from SecondViewController by using </p>
  
  <pre><code>[self.parentViewController hideSecondViewController];
  </code></pre>
  
  <p>But since parentViewController is defined as a UIViewController, and hideSecondViewController isn't a method of UIViewController, I get a warning saying "UIViewController may not respond to 'hideSecondViewController'".  It works fine, because it CAN send the message successfully during the program, but since I #import SecondViewController in MyViewController, I can't #import MyViewController in SecondViewController.  Any way around this?</p>