protected override async void OnNavigatedTo(NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);
            Analytics.TrackEvent("Navigation", new Dictionary <string, string>()
            {
                { "Page", "CalendarSubscription" }
            });
            if (!(e.Parameter is string username))
            {
                throw new ArgumentException("Required username parameter is not provided or not recognized.");
            }
            ICalendarSubscriptionService service = Application.Current.GetService <ICalendarSubscriptionService>();

            ViewModel = new CalendarSubscriptionViewModel(username, service);
            await ViewModel.UpdateAsync();
        }
 public CalendarSubscriptionViewModel(string username, ICalendarSubscriptionService calendarService)
 {
     this.username        = username;
     this.calendarService = calendarService;
 }