code: protected boolean isBlockedJob(String jobHashKey, T jedis) {
          JobKey jobKey = redisSchema.jobKey(jobHashKey);
          return jedis.sismember(redisSchema.blockedJobsSet(), jobHashKey) &&
                  isActiveInstance(jedis.get(redisSchema.jobBlockedKey(jobKey)), jedis);
      }
docs: Determine if the given job is blocked by an active instance
  @param jobHashKey the job in question
  @param jedis a thread-safe Redis connection
  @return true if the given job is blocked by an active instance