columnar::ParticleDef Node1 columnar::ParticleDef + idName   Node3 columnar::Particle1Def + idName   Node1->Node3 Node4 columnar::Particle2Def + idName   Node1->Node4 Node2 columnar::RegularContainer Id< xAOD::IParticle, xAOD ::IParticleContainer > + isContainerId + regularObjectId + variantObjectId + regularColumnAccessorArray + isMutable + perEventRange + perEventId   Node2->Node1