TrackTraitsBase< T > Node1 TrackTraitsBase< T >   + pt() + eta() + theta() + phi() + z0() + d0() + qOverP() + p() + m() + E() and 31 more... Node2 TrackTraits< const T >   + pt() + eta() + theta() + phi() + z0() + d0() + qOverP() + p() + m() + E() and 31 more... Node1->Node2 Node3 TrackTraits< T >     Node1->Node3 Node3->Node2