title: Register nib with collectionview
body: <p>I have FeedCell.swift and FeedCell.xib, in feedcell xib i set cell custom class to 'FeedCell' </p>
  
  <p>Code in view controller viewDidLoad </p>
  
  <pre><code>collectionView.register(UINib(nibName: "FeedCell", bundle: .main), forCellWithReuseIdentifier: "feedCell")
  </code></pre>
  
  <p><strong>Problem</strong>: </p>
  
  <p>I want to subclass FeedCell and use that class with collectionView
  Like:</p>
  
  <pre><code>class FeedCell:UICollectionViewCell {
      @IBOutlet weak var showImageView: UIImageView!
      @IBOutlet weak var showIconImageView: UIImageView!
  
  }
  
  class AppFeedCell: FeedCell { 
      override func awakeFromNib() {
         super.awakeFromNib()
         // configure cell
      }
  }
  </code></pre>
  
  <p>How to register/use FeedCell and AppFeedCell with collectionview?</p>