Redis pipeline usage

I'm trying to understand how pipeline works nad want to try something different. I've noticed that there's no method for setting expire key if the key doesn't have any so I made an example for that with Jedis.

Example

Map<String, Response> responses = new HashMap<>();long start = System.currentTimeMillis();try (Jedis resource = redisManager.getResource()) {    Pipeline pipeline = resource.pipelined();    responses.put("time", pipeline.ttl(args[1]));    pipeline.sync();    pipeline.multi();    if (responses.get("time").get().equals(-1L)) {        pipeline.expire(args[1], 15);    }    pipeline.exec();}

I'd like to know that should I use like that or do you have any idea about it? I couldn't find any solution for that.