private static <K> List<Object> doConcurrentGet(
      LoadingCache<K, ?> cache, K key, int nThreads, CountDownLatch gettersStartedSignal)
      throws InterruptedException {

    AtomicReferenceArray<Object> result = new AtomicReferenceArray<>(nThreads);
    CountDownLatch gettersComplete = new CountDownLatch(nThreads);
    for (int i = 0; i < nThreads; i++) {
      int index = i;
      Thread thread =
          new Thread(