completed.assertCompletionNotExpected(timeoutMillis);
    }

    private void tryAcquireUnsuccessfully(int permits, long timeoutMillis) {
      assertFalse(tryAcquireUninterruptibly(semaphore, permits, timeoutMillis, MILLISECONDS));
      completed.assertCompletionNotExpected(timeoutMillis);
    }

    private void scheduleRelease(long countdownInMillis) {