 
     private weak var passcodeViewController: UIViewController?
     
+    private var backgroundTimestamp: Date?
+    public var backgroundTimeout: TimeInterval = 5 * 60
+    
     /**
      Is the passcode blocking?
      */

    }
    
    open func applicationWillEnterForeground(_ application: UIApplication) {
        lockScreen()
    }
    
    open func application(_ application: UIApplication, didRegister notificationSettings: UIUserNotificationSettings) {

    open func presentViewController(_ viewController: UIViewController, animated: Bool, completion: (() -> Void)?) {
        guard let rootVC = self.window?.rootViewController else { return }
        var topViewController: UIViewController = rootVC
        while let presentedVC = topViewController.presentedViewController {
            if presentedVC.modalPresentationStyle != .fullScreen {
                presentedVC.dismiss(animated: false, completion: nil)
                break
            }
            else {
                topViewController = presentedVC
            }
        }
        topViewController.present(viewController, animated: animated, completion: completion)
    }
