public NavigationViewModel(IFolderRepository folderRepository, INavigationService navigationService)
        {
            _folderRepository  = folderRepository;
            _navigationService = navigationService;
            SelectedFolder     = _folderRepository.GetRootFolder();
            GarbageFolder      = _folderRepository.GetGarbageFolder();

            if (IsInDesignMode)
            {
                NavigationViewMode = NavigationViewMode.Default;
            }
        }