title: UIImageView transition between different images with animation
body: <p>i have this code which repeating fade in the same picture to the view controller forever</p>
  
  <pre><code> override func viewDidAppear(_ animated: Bool) {
          let toImage = UIImage(named:"intro.png")
          UIView.transition(with: self.imageView,
                            duration:2,
                            options: [.repeat , .transitionCrossDissolve],
                            animations: { self.imageView.image = toImage},
                            completion: nil)
  
  
      }
  </code></pre>
  
  <p>Now i need it to such between four images every time fade in with different img for ever.</p>