G4UA::G4TrackCounterTool Node1 G4UA::G4TrackCounterTool + G4TrackCounterTool() + initialize() + finalize() # makeAndFillAction() Node2 G4UA::UserActionToolBase < G4TrackCounter > # m_actions + UserActionToolBase() + fillUserAction() # makeAndFillAction() Node2->Node1 Node3 extends< AthAlgTool, IUserActionTool > Node3->Node2