Trk::MVFVxTrackAtVertex_p1 Node1 Trk::MVFVxTrackAtVertex_p1 + MVFVxTrackAtVertex_p1() Node2 TPObjRef # m_index + TPObjRef() + TPObjRef() + isNull() + typeID() + topLevelCnvID() + index() Node2->Node1 +m_vxTrackAtVertex Node3 TPObjRef::typeID_t + m_TLCnvID + m_cnvID + typeID_t() + topLevelCnvID() + cnvID() + value() + isNull() Node3->Node2 #m_typeID