title: Fatal error: unexpectedly found nil while unwrapping an Optional values
body: <p>I was using an <code>UICollectionView</code> in Swift but I get   when I try to change the text of the cell's label.</p>
  
  <pre><code>    func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -&gt; Int
  {
      return 5
  }
  
  func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -&gt; UICollectionViewCell!
  {
      var cell = collectionView.dequeueReusableCellWithReuseIdentifier("title", forIndexPath: indexPath) as TitleCollectionViewCell
      // Next line: fatal error: unexpectedly found nil while unwrapping an Optional value
      cell.labelTitle.text = "This is a title"
      return cell
  }
  </code></pre>
  
  <p>Does anyone know about this?</p>
  
  <p><a href="https://i.stack.imgur.com/3yJiY.png"><img src="https://i.stack.imgur.com/3yJiY.png" alt="Screenshot for warning on Console"></a></p>