var header : StretchHeader!

 override func viewDidLoad() {
       super.viewDidLoad()
       
       tableView.register(UITableViewCell.self, forCellReuseIdentifier: "TableViewCell")
       
       setupHeaderView()
   }
   
   func setupHeaderView() {
       
       let options = StretchHeaderOptions()
       options.position = .underNavigationBar
       
       header = StretchHeader()
       header.stretchHeaderSize(headerSize: CGSize(width: view.frame.size.width, height: 220),
           imageSize: CGSize(width: view.frame.size.width, height: 220),
           controller: self,
           options: options)
       header.imageView.image = UIImage(named: "photo_sample_05")
       
       // custom
       let label = UILabel()
       label.frame = CGRect(x: 10, y: header.frame.size.height - 40, width: header.frame.size.width - 20, height: 40)
       label.textColor = UIColor.white
       label.text = "StrechHeader Demo"
       label.font = UIFont.boldSystemFont(ofSize: 16)
       header.addSubview(label)
       
       tableView.tableHeaderView = header
   }
   
   // MARK: - ScrollView Delegate
   override func scrollViewDidScroll(_ scrollView: UIScrollView) {
       header.updateScrollViewOffset(scrollView)
   }