for(set<Sensor *>::iterator i=sensors.get().begin(); i!=sensors.get().end(); ++i)
(*i)->tick(dt);
const set<Signal *> &signals = objects.get<Signal>();
for(set<Signal *>::iterator i=signals.begin(); i!=signals.end(); ++i)
(*i)->tick(dt);
for(map<unsigned, Train *>::iterator i=trains.begin(); i!=trains.end(); ++i)
for(set<Sensor *>::iterator i=sensors.get().begin(); i!=sensors.get().end(); ++i)
(*i)->tick(dt);
const set<Signal *> &signals = objects.get<Signal>();
for(set<Signal *>::iterator i=signals.begin(); i!=signals.end(); ++i)
(*i)->tick(dt);
for(map<unsigned, Train *>::iterator i=trains.begin(); i!=trains.end(); ++i)