Iterator i = assignments.iterator();
Assignment assignment;
ArrayList detail=new ArrayList(assignments.size());
while (i.hasNext()) {
assignment = (Assignment)i.next();
detail.add(assignment.backupDetail());
}
return new TaskSnapshotBackup(snapshot.getCurrentSchedule(),detail);
}
public static void restore(TaskSnapshot snapshot,TaskSnapshotBackup backup){
if (backup==null||snapshot==null) return;