title: Add UILabel to Custom UICollectionViewCell doesn't appear in cellForItemAtIndexPath
body: <p>I am new to UICollectionView. I am trying to add Two UILabel to my Custom <code>UICollectionViewCell</code> like following.</p>
  
  <pre><code>@interface PassCell : UICollectionViewCell
  
  @property (nonatomic) IBOutlet UILabel *titleLabel;
  @property (nonatomic) IBOutlet UIButton *infoButton;
  @property (nonatomic) IBOutlet UIButton *doneButton;
  @property (nonatomic) IBOutlet UILabel *headerTitle;
  </code></pre>
  
  <p>I have already connected with <code>UILabel</code> in <code>Storyboard</code>.
  However When i set headerTitle in <code>CellforITemAtIndexPath</code> , headerTitle <code>UILabel</code> doesn't appearing. Only titleLabel can set value.</p>
  
  <pre><code>- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
  {
      PassCell *cell = (PassCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"pass" forIndexPath:indexPath];
  
      cell.titleLabel.shadowColor = [UIColor blackColor];
      cell.titleLabel.textColor = [UIColor whiteColor];
      cell.titleLabel.shadowOffset = CGSizeMake(0, 1);
  
      cell.titleLabel.text = @"Test";
      cell.headerTitle.text // That doesn't appear.
  
      return cell;
  }
  </code></pre>
  
  <p>What's wrong with my codes?</p>