code: def from_json(cls, json_info):
          
          if json_info is None:
              return None
          return JobRecord(
              job_id=json_info["job_id"],
              name=json_info["job_name"],
              user=json_info["user"],
              type=json_info["type"],
              start_time=json_info["start_time"])
docs: Build a Job instance from a json string.