Building
Building::House
Building::Shed
Building::Garage
Vehicle
Vehicle::Car
Vehicle::Train
Vehicle::Motorcycle
Door
Door::Hinged
Door::Sliding
Door::Roller

##</code><code>##

Building
Building::House
Building::House::Door
Building::House::Door::Hinged
Building::House::Door::Sliding
Building::Shed
Building::Shed::Door
Building::Shed::Door::Hinged
...
Vehicle
Vehicle::Train
Vehicle::Train::Door
Vehicle::Train::Door::Hinged
Vehicle::Train::Door::Sliding
...