Custom ItemsControl: Validating the ItemsControl's ItemsPanel and ItemsSource?

Hi,

I created my own custom panel and i am creating a custom itemscontrol which only can use the custom panel. How should i override the metadata for the ItemsPanelProperty to make sure that the panel is my custom panel?

Same goes for the ItemsSource, how should i make sure the ItemsSource is an IEnumerable<MyCustomClass>?