title: Presenting a UIViewController without animation shows the presenter UIViewController for an istant
body: <pre><code>// AppDelegate.swift
  
  let navigationController = UINavigationController()
  self.window = UIWindow(frame: UIScreen.main.bounds)
  self.window!.rootViewController = navigationController
  self.window!.makeKeyAndVisible()
  
  let homeViewController = HomeViewController()
  navigationController.pushViewController(homeViewController, animated: false)
  if !isLoggedIn {
      let authViewController = AuthViewController()
      navigationController.present(authViewController, animated: false)
  }
  </code></pre>
  
  <p>I have a situation similar to this. If no user is authenticated, I want to show the authentication screen. The code above works but the problem is that, for a fraction of a second, I can see the HomeViewController before the AuthViewController is presented modally without animation. How can I prevent that?</p>
  
  <p>Here's a GIF showing the problem.</p>
  
  <p><a href="https://i.stack.imgur.com/Mzuc1.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Mzuc1.gif" alt="Animation"></a></p>
  
  <p>Edit: I wouldn't want to use and if/else statement. I would like HomeViewController to always sit underneath AuthViewController.</p>