@Test
  public void testRequestToObservable() {
    TestSubscriber<Integer> ts = new TestSubscriber<>();
    ts.request(3);
    final AtomicLong requested = new AtomicLong();
    Observable.<Integer>create(
            s ->
                s.onSubscribe(
                    new Subscription() {

                      @Override
                      public void request(long n) {
                        requested.set(n);
                      }

                      @Override
                      public void cancel() {}
                    }))
        .subscribe(ts);
    assertEquals(3, requested.get());
  }
  @Test
  public void testRequestThroughTakeWhereRequestIsSmallerThanTake() {
    TestSubscriber<Integer> ts = new TestSubscriber<>((Long) null);
    ts.request(3);
    final AtomicLong requested = new AtomicLong();
    Observable.<Integer>create(
            s ->
                s.onSubscribe(
                    new Subscription() {

                      @Override
                      public void request(long n) {
                        requested.set(n);
                      }

                      @Override
                      public void cancel() {}
                    }))
        .take(10)
        .subscribe(ts);
    assertEquals(3, requested.get());
  }
  @Test
  public void testRequestThroughTakeThatReducesRequest() {
    TestSubscriber<Integer> ts = new TestSubscriber<>((Long) null);
    ts.request(3);
    final AtomicLong requested = new AtomicLong();
    Observable.<Integer>create(
            s ->
                s.onSubscribe(
                    new Subscription() {

                      @Override
                      public void request(long n) {
                        requested.set(n);
                      }

                      @Override
                      public void cancel() {}
                    }))
        .take(2)
        .subscribe(ts);

    // FIXME the take now requests Long.MAX_PATH if downstream requests at least the limit
    assertEquals(Long.MAX_VALUE, requested.get());
  }