private async Task StartupAsync()
        {
            await ThemeSelectorService.SetRequestedThemeAsync();

            await Task.CompletedTask;
        }
        private async Task InitializeAsync()
        {
            await Singleton <BackgroundTaskService> .Instance.RegisterBackgroundTasksAsync().ConfigureAwait(false);

            await ThemeSelectorService.InitializeAsync().ConfigureAwait(false);
        }