code: def job_success(self, job, queue, job_result):
          
          job.queued.delete()
          job.hmset(end=str(datetime.utcnow()), status=STATUSES.SUCCESS)
          queue.success.rpush(job.ident)
          self.log(self.job_success_message(job, queue, job_result))
          if hasattr(job, 'on_success'):
              job.on_success(queue, job_result)
docs: Called just after an execute call was successful.
          job_result is the value returned by the callback, if any.