Nested types

I would like to nest types.

I now have four types for a Gallery; Gallery, GalleryItem, GalleryPhotoItem and GalleryVideoItem. I'm inheriting the GalleryPhotoItem and GalleryVideoItem from the GalleryItem. These types cannot function without the GalleryItem. Therefore I would like to nest them within the GalleryItem.

Gallery
GalleryItem

• Video(Item)
• Photo(Item)