const std::set<R2C2::Track *> &get_tracks() const { return tracks; }
R2C2::Track *get_track() const;
unsigned size() const { return tracks.size(); }
const std::set<R2C2::Track *> &get_tracks() const { return tracks; }
R2C2::Track *get_track() const;
unsigned size() const { return tracks.size(); }