Prevents the window from being displayed for Mac Catalyst.

dummy.swift

class DummyViewController: UIViewController {
    
    deinit {
        print(#function)
    }
    
    required init?(coder: NSCoder) {
        print(#function)
        super.init(coder: coder)
    }
    
    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
        print(#function)
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        UIApplication.shared.connectedScenes.forEach { (scene) in
            if let uiscene = scene as? UIWindowScene {
                uiscene.windows.forEach { (window) in
                    if window.rootViewController == self {
                        UIApplication.shared.requestSceneSessionDestruction(uiscene.session, options: .none) { (error) in
                            print(error)
                        }
                    }
                }
            }
        }
    }
}