public ShellViewModel(INavigationService navigationService, TestClass @class)
 {
     NavigationCommand = ConfigurableCommand.Create(
         o =>
     {
         var name = o as string;
         navigationService.NavigateTo(name);
     }).Build();
 }
 public Page1ViewModel()
 {
     MyCommand = ConfigurableCommand.Create(o => { })
                 .ObserveAll(this)
                 .Build();
 }