title: Error: Multiple inheritance from classes 'UICollectionViewController' and 'UICollectionViewLayout'
body: <p>In Xcode 8 I'm trying to make a subclass of UICollectionViewController and UICollectionViewLayout but I get the error: </p>
  
  <blockquote>
    <p>Multiple inheritance from classes 'UICollectionViewController' and 'UICollectionViewLayout'</p>
  </blockquote>
  
  <p>but they have different parents classes. I'm trying to follow <a href="http://nshint.io/blog/2015/07/16/uicollectionviews-now-have-easy-reordering/" rel="nofollow">http://nshint.io/blog/2015/07/16/uicollectionviews-now-have-easy-reordering/</a> tutorial for reorder custom size cells</p>
  
  <pre><code>class WordCollectionViewController: UICollectionViewController, UICollectionViewLayout {
      // ...
      override func invalidationContext(forInteractivelyMovingItems targetIndexPaths: [IndexPath], withTargetPosition targetPosition: CGPoint, previousIndexPaths: [IndexPath], previousPosition: CGPoint) -&gt; UICollectionViewLayoutInvalidationContext {
              var context = super.invalidationContext(forInteractivelyMovingItems: targetIndexPaths, withTargetPosition: targetPosition, previousIndexPaths: previousIndexPaths, previousPosition: previousPosition)
  
          return context
      }
  }
  </code></pre>