G4UA::SG_StepNtupleTool Node1 G4UA::SG_StepNtupleTool - m_pdgids + SG_StepNtupleTool() # makeAndFillAction() Node2 G4UA::UserActionToolBase < SG_StepNtuple > # m_actions + UserActionToolBase() + fillUserAction() # makeAndFillAction() Node2->Node1 Node3 extends< AthAlgTool, IUserActionTool > Node3->Node2