@Override
    public int availablePermits() {
        return get(availablePermitsAsync());
    }
@Test
    public void testNotExistent() {
        RPermitExpirableSemaphore semaphore = redisson.getPermitExpirableSemaphore("testSemaphoreForNPE");
        Assertions.assertEquals(0, semaphore.availablePermits());
    }