public PostLoginViewModel()
        {
            var sc =
                new DesignTimeSecurityContext
            {
                CurrentUser = new Employee {
                    FirstName = "Fred", LastName = "Jones"
                }
            };

            SecurityContext = sc;
        }
 public MainWindowViewModel()
 {
     MessageBus        = new MessageBus();
     SecurityContext   = new DesignTimeSecurityContext();
     FullScreenContent = new LoginViewModel(DataService, MessageBus);
 }