title: Does UIAlertController's dismiss method without animation execute synchronously?
body: <p>If I call (In an <code>UIViewController</code>)</p>
  
  <pre><code>alert.dismiss(animated: false, completion: nil)
  print("executed after dismiss?")
  </code></pre>
  
  <p>Given that alert is a previously presented <code>UIAlertController</code>, does the dismiss method execute synchronously?</p>
  
  <p>Could I do:</p>
  
  <pre><code>alert.dismiss(animated: false, completion: nil)
  let newAlert = UIAlertController(...)
  present(newAlert, animated: true, completion: nil)
  </code></pre>
  
  <p>Without having to worry about a problem while presenting <code>newAlert</code>?</p>