 class ViewController: UIViewController {
     
     @IBOutlet weak var collectionView: UICollectionView!
+    
+    fileprivate var cellSize: CGSize?
     
     override func viewDidLoad() {
         super.viewDidLoad()

        
        let width = UIScreen.main.bounds.width - 60 // 30 margin aan beide kanten
        
        let height = collectionView.frame.height - 100 // 70 margin hoogte
        
        return CGSize(width: width, height: height)
    }
}

extension ViewController {

        
        collectionView.delegate = self
        collectionView.dataSource = self
        collectionView.bounces = false
    }
    
    fileprivate func setupScrollView(){
        
        // inset bovenaan instellen
        collectionView.contentInset = UIEdgeInsets(top: 30, left: 0, bottom: 0, right: 0)
    }
}
