@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil) -> Bool {
    // ...

    window = UIWindow(bounds: UIScreen.main.bounds)
    window.rootViewController = PostNLRootViewController()
    window.makeKeyAndVisible()
    // ...
    return true
  }
}