MuonTrackPerformanceAlg::TrackSummary Node1 MuonTrackPerformanceAlg ::TrackSummary Node2 std::string Node2->Node1 +trackPars +chambers Node4 std::vector< std::string > Node2->Node4 +elements Node3 std::basic_string< char > Node3->Node2 Node4->Node1 +missingChambers