BeamSpot::Event Node1 BeamSpot::Event + pileup + runNumber + lumiBlock + bcid Node2 std::vector< BeamSpot ::VrtHolder > Node2->Node1 +vertices Node3 BeamSpot::VrtHolder + x + y + z + vxx + vxy + vyy + vzz + vertexType + nTracks + passed + valid + VrtHolder() Node3->Node2 +elements Node4 long Node4->Node1 +eventTime +eventNumber +eventTime_NS