void set_destination(const TrackChain &);
const TrackChain *get_destination() const { return destination; }
bool is_destination(Track &) const;
void add_waypoint(const TrackChain &);
unsigned get_n_waypoints() const { return waypoints.size(); }
bool is_waypoint(unsigned, Track &) const;
void set_destination(const TrackChain &);
const TrackChain *get_destination() const { return destination; }
bool is_destination(Track &) const;
void add_waypoint(const TrackChain &);
unsigned get_n_waypoints() const { return waypoints.size(); }
bool is_waypoint(unsigned, Track &) const;