final FlatJoinFunction<IntPair, Record, Record> matcher = new RecordIntPairMatchRemovingMatcher(expectedMatchesMap);
final Collector<Record> collector = new DiscardingOutputCollector<Record>();
// reset the generators
input1 = new UniformIntPairGenerator(500, 40, false);
generator2.reset();
input2.reset();
// compare with iterator values
BuildSecondHashMatchIterator<IntPair, Record, Record> iterator =
new BuildSecondHashMatchIterator<IntPair, Record, Record>(