code: public long indexOf(final String element) {
          return doWithJedis(new JedisCallable<Long>() {
              @Override
              public Long call(Jedis jedis) {
                  return doIndexOf(jedis, element);
              }
          });
      }
docs: Find the index of the first matching element in the list
  @param element the element value to find
  @return the index of the first matching element, or <code>-1</code> if none found