public void TestInitialize()
 {
     factories = Substitute.For<Factories>();
     fixture = new Fixture();
     factories.Finder.Returns(new FinderImpl(factories));
     factories.CreateCategory().Returns(new Category());
     factories.Categories.Returns(fixture.CreateMany<Category>().ToList());
     factories.Products.Returns(fixture.CreateMany<Product>(5).ToList());
     foreach (var product in factories.Products)
     {
         product.CategoryId = factories.Categories[1].Id;
         product.SetOwner(factories);
     }
     factories.MruProducts.Returns(new MruProductsImpl(new List<Guid>(), factories));
     factories.Settings.Returns(new Settings());
     viewModel = new ProductListingViewModel(factories, new BackgroundWorkerSyncFactory());
 }