@Override
    public boolean retainAll(Collection<?> c) {
        return get(retainAllAsync(c));
    }
@Test
    public void testRetainAll() {
        RScoredSortedSet<Integer> set = redisson.getScoredSortedSet("simple");
        for (int i = 0; i < 20000; i++) {
            set.add(i*10, i);
        }

        assertThat(set.retainAll(Arrays.asList(1, 2))).isTrue();
        assertThat(set).containsExactly(1, 2);
        assertThat(set.size()).isEqualTo(2);
        assertThat(set.getScore(1)).isEqualTo(10);
        assertThat(set.getScore(2)).isEqualTo(20);
    }