@Test
  void oneOrNone() {
    check(Flowable.fromPublisher(create().oneOrNone()).toList().blockingGet()).isEmpty();
    check(Flowable.fromPublisher(create("one").oneOrNone()).toList().blockingGet()).hasContentInAnyOrder("one");
    Assertions.assertThrows(NonUniqueResultException.class, () -> {
      // two
      Flowable.fromPublisher(create("one", "two").one()).toList().blockingGet();
    });
  }
Check that correct exceptions are thrown by {@link ReactiveFetcher}
criteria/common/test/org/immutables/criteria/repository/reactive/ReactiveFetcherDelegateTest.java