TRTCalibrator::BDstraw Node1 TRTCalibrator::BDstraw Node2 std::map< std::string, TRTCalibrator::BDzero > Node2->Node1 +s Node3 TRTCalibrator::BDzero + z Node3->Node2 +elements Node4 std::string Node4->Node2 +keys Node5 std::basic_string< char > Node5->Node4