// ITIterator iti = new TestPackage.ITIterator(db.iterator());
POPackage pop = new POPackage(new OperatorKey("", r.nextLong()));
pop.setNumInps(2);
pop.getPkgr().setInner(inner);
PigNullableWritable k = HDataType.getWritableComparableTypes(key, keyType);
pop.attachInput(k, db.iterator());
if (keyType != DataType.BAG) {
// test serialization
NullablePartitionWritable wr;
if (keyType == DataType.TUPLE) {
BinSedesTuple tup = (BinSedesTuple) binfactory.newTupleNoCopy(((Tuple) k.getValueAsPigType()).getAll());