if (partitioner.isIO(t1)) {  if (t1.getTail().isFileReader()) return true; if (t2.getTail().isFileReader()) return false;  if (t1.getHead().isFileWriter()) return false; if (t2.getHead().isFileWriter()) return true; }
    public boolean scheduledBefore(Trace t1, Trace t2)     {	assert schedule.contains(t1) && schedule.contains(t2) &&	    t1 != t2;	if (schedule.indexOf(t1) < schedule.indexOf(t2))	    return true;	return false;    }