title: Pass data to rear view using SWrevealviewcontroller
body: <p>I need to pass front ViewController to rear ViewController using SWRevealViewController, but I completely don't know how to do it.</p>
  
  <p>The variable in rear view looks like this:</p>
  
  <pre><code>var mainView : ViewController!
  </code></pre>
  
  <p>Any suggestions how to pass into it front ViewController?</p>