title: How do I create a UIImage from a CGImage in Swift?
body: <p>I'm trying to create a <code>UIImage</code> from the <code>ALAssetsGroup#posterImage</code> method. In Objective-C, I could simply call <code>[UIImage imageWithCGImage:group.posterImage]</code> but in Swift, <code>UIImage(CGImage: group.posterImage)</code> gives me a compiler error:</p>
  
  <pre><code>Could not find an overload for 'init' that accepts the supplied arguments
  </code></pre>
  
  <p>What am I doing wrong?</p>