public void ShowNotePad()
        {
            var window  = new NotePadViewModel();
            var message = new TransitionMessage(window, "Show/NotePad");

            this.Messenger.RaiseAsync(message);
        }
        public void ShowNotePad()
        {
            var catalog = new NotePadViewModel();

            WindowService.Current.MainWindow.Transition(catalog, typeof(NotePad));
        }