@Override
    public Long dbSize(RedisClusterNode node) {
        return execute(node, RedisCommands.DBSIZE);
    }
@Test
    public void testDbSize() {
        testInCluster(connection -> {
            connection.flushAll();
            RedisClusterNode master = getFirstMaster(connection);
            Long size = connection.dbSize(master);
            assertThat(size).isZero();
        });
    }