int nTasks = 3000;
    int nThreads = 100;
    final int getsPerTask = 1000;
    final int deltaRange = 10000;
    final String key = "key";

    final AtomicLongMap<String> map = AtomicLongMap.create();

    ExecutorService threadPool = Executors.newFixedThreadPool(nThreads);
    ArrayList<Future<Long>> futures = new ArrayList<>();
    for (int i = 0; i < nTasks; i++) {
      futures.add(