public void TestCommand()
        {
            _IWebServicesSettings = Substitute.For<IDiscogsAuthentificationProvider>();
            _Infra = Substitute.For<IInfraDependencies>();
            FileSystem fs = new FileSystem();
            _Infra.File.Returns(fs);

            _Target = new ExportKeyViewModel(_IWebServicesSettings, _Infra);
    
            ICommand com = _Target.Commit;
            com.MonitorEvents();

            com.Should().NotBeNull();
            com.CanExecute(null).Should().BeTrue();

            com.ShouldNotRaise("CanExecuteChanged");

            _Target.Directory = "24";

            com.CanExecute(null).Should().BeFalse();
            com.ShouldRaise("CanExecuteChanged");
   
            _Target.Directory = @"C:\";

            com.CanExecute(null).Should().BeTrue();
            com.ShouldRaise("CanExecuteChanged");
        }
 internal CurrentInfraTools(IMusicFactory imf)
 { 
     _Zipper = new SevenZipZipper();
     _Filer = new FileSystem();
     _MusicFactory = imf;
 }