title: Swift: Custom UINavigationController not called
body: <p>I want to change the root controller of my navigation controller programatically:</p>
  
  <pre><code>import UIKit
  import Foundation
  
  class NavigationController : UINavigationController {
      override init(rootViewController : UIViewController) {
          print("TEST")
          super.init(rootViewController : rootViewController)
      }
  
      override init(navigationBarClass: AnyClass?, toolbarClass: AnyClass?) {
          print("TEST2")
          super.init(navigationBarClass : navigationBarClass, toolbarClass : toolbarClass)
      }
  
      required init?(coder aDecoder: NSCoder) {
          super.init(coder: aDecoder)
      }
  }
  </code></pre>
  
  <p>I set the NavigationController class as custom class of my Navigation Controller in the storyboard</p>
  
  <p>The console does not show my test output. What am I doing wrong and how can I change the root controller here?</p>