title: Sound name from UNNotificationSound
body: <p>I am working with push notifications in CloudKit. Here is what I used before Swift 3:</p>
  
  <pre><code>notification.soundName = UILocalNotificationDefaultSoundName
  </code></pre>
  
  <p>(notification is a <code>CKNotificationInfo</code>)</p>
  
  <p>However, this gives me a warning:</p>
  
  <blockquote>
    <p>'UILocalNotificationDefaultSoundName' was deprecated in iOS 10.0: Use UserNotifications Framework's +[UNNotificationSound defaultSound]</p>
  </blockquote>
  
  <p>So I added the UserNotification framework to my Xcode project, and I imported it to my ViewController. I then tried this:</p>
  
  <pre><code>notification.soundName = UNNotificationSound.default()
  </code></pre>
  
  <p>However, this gives me an error:</p>
  
  <blockquote>
    <p>Cannot assign value of type 'UNNotificationSound' to type 'String?'</p>
  </blockquote>
  
  <p>So the default sound is a <code>UNNotificationSound</code>, but I need the sound name. How can I get the sound name from the sound? Thanks!</p>