public override void DidFinishLaunching(NSNotification notification)
        {
            var     sayer = new TestLib.Sayer();
            NSAlert alert = new NSAlert()
            {
                MessageText = TestHigherLib.TopLevelEntities.SayHello(sayer).ToString()
            };

            alert.RunModal();
            NSApplication.SharedApplication.Terminate(this);
        }
        public override void ViewDidAppear(bool animated)
        {
            base.ViewDidAppear(animated);

            var sayer = new TestLib.Sayer();
            UIAlertController alert = new UIAlertController()
            {
                Message = TestHigherLib.TopLevelEntities.SayHello(sayer).ToString()
            };

            alert.AddAction(UIAlertAction.Create("OK", UIAlertActionStyle.Default, null));
            PresentViewController(alert, true, null);
        }