  @Test
  public void testThatYouCannotBuyIfThereIsNotEnoughShare(TestContext tc) {

    Async async = tc.async();
    service.buy(100, quote("A", 10, 20, 10), ar -> {
      tc.assertTrue(ar.failed());
      tc.assertTrue(ar.cause().getMessage().contains("not enough stocks"));
      async.complete();
    });
  }