System.out.println("Schedule: ");
SpaceTimeBackend.println("Schedule: ");
    private void printSchedule() {        Iterator sch = schedule.iterator();        Trace prev = null;        System.out.println("Schedule: ");        while (sch.hasNext()) {            Trace trace = (Trace) sch.next();            System.out.println(" ** " + trace);                     prev = trace;        }    }