int get_endpoint_by_link(const Block &) const;
unsigned traverse(unsigned, float * =0) const;
void check_link(Block &);
int get_endpoint_by_link(const Block &) const;
unsigned traverse(unsigned, float * =0) const;
void check_link(Block &);
void print_debug();
private:
void find_paths(Track &, unsigned, unsigned, std::set<Track *> &);
void print_debug();
private:
void find_paths(Track &, unsigned, unsigned, std::set<Track *> &);