GenParticle_p1 Node1 GenParticle_p1 # m_px # m_py # m_pz # m_ene # m_pdgId # m_status # m_thetaPolarization # m_phiPolarization # m_prodVtx # m_endVtx # m_barcode + GenParticle_p1() + GenParticle_p1() Node2 std::vector< std::pair < int, int > > + elements Node2->Node1 #m_flow