title: How to make UIPopoverPresentationController semi transparent for iOS 9
body: <p>I used IB to create a segue to present another view a popover.</p>
  
  <p>I added a code in <code>prepareForSegue</code> to deletage UIPopoverPresentationControllerDelegate to initial controller.</p>
  
  <p>And I set presentation style:</p>
  
  <pre><code>func adaptivePresentationStyleForPresentationController(controller: UIPresentationController,
       traitCollection: UITraitCollection) -&gt; UIModalPresentationStyle {
        return UIModalPresentationStyle.None
  }
  </code></pre>
  
  <p>This gives me a nice standard popover.</p>
  
  <p>However, I want to make a semi-transparent popover.</p>
  
  <p>I tried couple of things:</p>
  
  <ul>
  <li>I set background color in IB to "clear"</li>
  <li>I tried to set a alpha on the popover view</li>
  </ul>