}
public void poSortUDFWithNull(DataBag input) throws ExecException {
PORead read = new PORead(new OperatorKey("", r.nextLong()), input);
List<PhysicalOperator> inputs = new LinkedList<PhysicalOperator>();
inputs.add(read);
String funcName = WeirdComparator.class.getName() + "()";
/*POUserFunc comparator = new POUserFunc(
new OperatorKey("", r.nextLong()), -1, inputs, funcName);*/