EDEPTrajectory should store information on the first/last trajectory point in each subdetector, if any. Best place to fill in such info is the EDEPTrajectory constructor. The information should be stored as an iterator to the wanted points in the `trajectory_points_` vector. A possible solution: `std::map<component, EDEPTrajectoryHits::iterator> last_points` `std::map<component, EDEPTrajectoryHits::iterator> first_points` `EDEPTrajectoryHits::iterator GetFirstPointInDetector(component)` `EDEPTrajectoryHits::iterator GetLastPointInDetector(component)`