public void duplicate() throws Exception {
TestInput<Ex1> in = tester.input(Ex1.class, "in");
TestOutput<Ex1> out = tester.output(Ex1.class, "out");
in.add(new Ex1());
boolean result = tester.runFlow(new DuplicateStage(in.flow(), out.flow()));
assertThat(result, is(true));
List<Ex1> outputs = out.toList();
assertThat(outputs.size(), is(2));
assertThat(outputs.get(0), equalTo(outputs.get(1)));