public void model_save_method_is_not_called_if_product_exists()
{
var product = new Product {
Code = "A1", Description = "A1 Desc", Price = 1.0
};
mockProductModel.Stub(p => p.ProductExists(product)).IgnoreArguments().Return(true);
RaiseAddButtonPressed(product);
mockProductModel.AssertWasNotCalled(m => m.Save(product));
}