[solved] Obtaining rigidBody from ContactPair

Hi all,
I have a question about the class PhysicsWorld: how would you go on to get the rigidBody from a ContactPair object?
in the contactPair there are some ints a and b that I guess are some kind of Id for the objects involved in the collision, how can I use those ids?
Also how complicated would it be to add a reference to the rigidBody contacted in the contactPair class?