title: Photos framework image from video at a certain frame
body: <p>I have made a library collectionview filled with videos i fetch from the Photos framework, i use thumbnails to display all the different videos using the following method</p>
  
  <pre><code>func requestImageForAsset(_ asset: PHAsset!, targetSize targetSize: CGSize, contentMode contentMode: PHImageContentMode, options options: PHImageRequestOptions!, resultHandler resultHandler: ((UIImage!, [NSObject : AnyObject]!) -&gt; Void)!) -&gt; PHImageRequestID
  </code></pre>
  
  <p>which works fine.
  But my videos always start with a black frame, so all the thumbnails are black. can I offset the frame from which it takes a snapshot image? </p>