public void returns_missing_instance_if_it_exists_and_the_requested_instance_is_not_found() { var graph = new PluginGraph(); var family = graph.Families[typeof (IWidget)]; var missing = new ObjectInstance(new AWidget()); family.MissingInstance = missing; graph.FindInstance(typeof (IWidget), "anything").ShouldBeTheSameAs(missing); graph.FindInstance(typeof (IWidget), Guid.NewGuid().ToString()).ShouldBeTheSameAs(missing); }