G4UA::SyncPrimaryGeneratorActionTool Node1 G4UA::SyncPrimaryGenerator ActionTool # m_g4RunTool + G4RunTool() # makeAndFillAction() Node2 G4UA::UserActionToolBase < SyncPrimaryGeneratorAction > # m_actions + UserActionToolBase() + fillUserAction() + BeginOfAthenaEvent() + EndOfAthenaEvent() # makeAndFillAction() Node2->Node1 Node3 extends< AthAlgTool, IUserActionTool >     Node3->Node2