public void testSleepMultiInterrupt() {
    repeatedlyInterruptTestThread(10, tearDownStack);
    sleepSuccessfully(100);
    assertInterrupted();
  }

  // Semaphore.tryAcquire() tests
  public void testTryAcquireWithNoWait() {
    Stopwatch stopwatch = Stopwatch.createStarted();
    Semaphore semaphore = new Semaphore(99);
    assertTrue(tryAcquireUninterruptibly(semaphore, 0, MILLISECONDS));