Represents a simple in-memory repository for the TodoListItems.
 /// <summary>
 /// Initializes a new <see cref="CreateTodoListItemViewModel"/> instance.
 /// </summary>
 /// <param name="navigationService">The navigation service, which is used to navigate between views.</param>
 /// <param name="applicationService">The application service, which can be used to manage the application lifecycle.</param>
 /// <param name="dialogService">The dialog service, which provides access to the various dialogs offered by Windows.</param>
 /// <param name="todoListItemsRepository">The todo list items repository, which can be used to manage the items on the todo list.</param>
 public CreateTodoListItemViewModel(NavigationService navigationService, ApplicationService applicationService, DialogService dialogService, TodoListItemsRepository todoListItemsRepository)
 {
     this.navigationService = navigationService;
     this.applicationService = applicationService;
     this.dialogService = dialogService;
     this.todoListItemsRepository = todoListItemsRepository;
 }
 /// <summary>
 /// Initializes a new <see cref="MainViewModel"/> instance.
 /// </summary>
 /// <param name="navigationService">The navigation service, which is used to navigate between views.</param>
 /// <param name="applicationService">The application service, which can be used to manage the application lifecycle.</param>
 /// <param name="todoListItemsRepository">The todo list items repository, which can be used to manage the items on the todo list.</param>
 public MainViewModel(NavigationService navigationService, ApplicationService applicationService, TodoListItemsRepository todoListItemsRepository)
 {
     this.navigationService = navigationService;
     this.applicationService = applicationService;
     this.todoListItemsRepository = todoListItemsRepository;
 }