@Override
    public boolean addIfExists(Duration ttl, V object) {
        return get(addIfExistsAsync(ttl, object));
    }
@Test
    public void testAddIfExists() throws InterruptedException {
        RSetCache<String> cache = redisson.getSetCache("list");
        cache.add("a", 1, TimeUnit.SECONDS);
        assertThat(cache.addIfExists(Duration.ofSeconds(2), "a")).isTrue();

        Thread.sleep(1500);
        assertThat(cache.contains("a")).isTrue();
        Thread.sleep(700);
        assertThat(cache.contains("a")).isFalse();
    }