List<Tuple2<Integer, Integer>> collected = new ArrayList<Tuple2<Integer, Integer>>();
iteration.closeWith(solDelta, nextWorkset)
.output(new LocalCollectionOutputFormat<Tuple2<Integer, Integer>>(collected));
env.execute();
// verify that both tuple fields are now the same
for (Tuple2<Integer, Integer> t: collected) {
assertEquals(t.f0, t.f1);
}