ex1.setValue(40);
in.add(ex1);
ex1.setValue(50);
in.add(ex1);
FlowDescription flow = new SimpleShuffleStage(in.flow(), out.flow());
assertThat(tester.runFlow(flow), is(true));
List<ExSummarized> list = out.toList(new Comparator<ExSummarized>() {
@Override
public int compare(ExSummarized o1, ExSummarized o2) {