bool update_states();
bool check_deadlocks() const;
int get_occupant(Track &) const;
int find_next_train() const;
void advance(const Msp::Time::TimeDelta &);
bool update_states();
bool check_deadlocks() const;
int get_occupant(Track &) const;
int find_next_train() const;
void advance(const Msp::Time::TimeDelta &);