title: UICollectionView Header title change
body: <p>I have a <code>UICollectionView</code> with 4 custom <code>UICollectionViewCells</code>. In the header of the <code>UICollectionView</code> there's a <code>UISegmentedControl</code>. My goal is to change the header <code>UILabel</code> that plays the role of a title. Right now if the segmented control value had been changed, the cells are reloaded and the title should be switched, but it overlaps with the first title. I can't figure out why.</p>
  
  <pre><code>func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -&gt; UICollectionReusableView {
      if kind == UICollectionElementKindSectionHeader {
          let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "HeaderDiscoverVC", for: indexPath) as! HeaderDiscoverVC
          headerView.frame = CGRect(x: 0, y: 0, width: collectionView.frame.width, height: 30)
          headerView.backgroundColor = UIColor.hex("d9e2e7")
          let label = UILabel(frame: CGRect(x: 16, y: 0, width: headerView.frame.width, height: 30))
  
          switch segReusableIdentifier {
          case "Reply":
              label.text = "Reply"
          case "Media":
              label.text = "Media"
          case "Likes":
              label.text = "Likes"
          case "Comments":
              label.text = "Comments"
          default:
              label.text = ""
          }
          label.font = UIFont(name: Fonts.OpenSans_Bold, size: 16)
          label.textColor = UIColor.hex("8a9da6")
          headerView.addSubview(label)
          return headerView
      }
  
     fatalError("Unexpected element kind")
  } 
  </code></pre>