void save(std::list<Msp::DataFile::Statement> &) const;
private:
Track &get_sensor(unsigned);
Track &get_turnout(unsigned);
Zone &get_zone(const std::string &);
void save(std::list<Msp::DataFile::Statement> &) const;
private:
Track &get_sensor(unsigned);
Track &get_turnout(unsigned);
Zone &get_zone(const std::string &);