title: indexPathForPreferredFocusedView is not being Called
body: <p>I need to specify which cell should receive focus.</p>
  
  <p>According to Apple Documentation the <code>indexPathForPreferredFocusedView</code> delegate method should be called if the <code>remembersLastFocusedIndexPath</code> property is <code>false</code>, or if there is no saved index path because no cell was previously focused.</p>
  
  <p>In my case I am using a collection view in a <code>UIViewController</code> and setting <code>remembersLastFocusedIndexPath</code> to <code>false</code> but <code>indexPathForPreferredFocusedView</code> is not being called.</p>
  
  <p>How explain this behaviour?</p>