source: class RxComprehensionsTest {
  
      @Test
      public void nineFM() {
  
target:         final TestSubscriber<Object> observer = TestSubscriber.create();
          RxComprehensions.doFlatMap(zero(1), one(true), two("result"), three("other"), four("other".length()),
                  five("other".length() < 5), six(Boolean.toString(false)), seven("true"), eight(Long.class),
                  this.<Long>nine()).subscribe(observer);
          observer.awaitTerminalEvent();
          observer.assertCompleted();
          observer.assertNoErrors();
          observer.assertValues(1, true, "result", "other", (long) "other".length(), "other".length() < 5,
                  Boolean.toString(false), false, Long.class);
      }
  
  }