#vulnerable code 
                              @Test
  public void test_local_quotes_service() throws InterruptedException {
    Microservices node = Microservices.builder().services(new SimpleQuoteService()).build();

    QuoteService service = node.call().api(QuoteService.class);

    CountDownLatch latch = new CountDownLatch(3);
    Flux<String> obs = service.quotes();

    Disposable sub = obs.subscribe(onNext -> latch.countDown());

    latch.await(4, TimeUnit.SECONDS);

    sub.dispose();
    assertTrue(latch.getCount() <= 0);
    node.shutdown();
  } 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                              @Test
  public void test_local_quotes_service() throws InterruptedException {
    Microservices node = Microservices.builder()
        .discoveryPort(port.incrementAndGet())
        .services(new SimpleQuoteService()).build();

    QuoteService service = node.call().api(QuoteService.class);

    CountDownLatch latch = new CountDownLatch(3);
    Flux<String> obs = service.quotes();

    Disposable sub = obs.subscribe(onNext -> latch.countDown());

    latch.await(4, TimeUnit.SECONDS);

    sub.dispose();
    assertTrue(latch.getCount() <= 0);
    node.shutdown();
  }