@Test
@Tag(Tags.Slow)
public void randomFiveThreads() throws InterruptedException {

    List<Throwable> uncaught = Collections.synchronizedList(new ArrayList<>());
    Thread[] threads = new Thread[5];
    for (int i = 0; i < threads.length; ++i) {
        threads[i] = new Thread(() -> {
            thousandRankedSetOps(db, newRankedSet());
        }, "RSTest" + i);
        threads[i].setUncaughtExceptionHandler((t, e) -> uncaught.add(e));
    }
    for (Thread t : threads) {
        t.start();
    }
    for (Thread t : threads) {
        t.join(60 * 1000);
    }
    assertEquals("[]", uncaught.toString());
}