code: public String pop() {
          return doWithJedis(new JedisCallable<String>() {
              @Override
              public String call(Jedis jedis) {
                  return jedis.spop(getKey());
              }
          });
      }
docs: Removes and returns a random element from the set.
  @return the removed element, or <code>null</code> when the key does not exist.