code: def _make_job_id(job_id, prefix=None):
      
      if job_id is not None:
          return job_id
      elif prefix is not None:
          return str(prefix) + str(uuid.uuid4())
      else:
          return str(uuid.uuid4())
docs: Construct an ID for a new job.
  
      :type job_id: str or ``NoneType``
      :param job_id: the user-provided job ID
  
      :type prefix: str or ``NoneType``
      :param prefix: (Optional) the user-provided prefix for a job ID
  
      :rtype: str
      :returns: A job ID