code: def mark_job_as_canceling(self, job_id):
          
  
          job, _ = self._update_job_state(job_id, State.CANCELING)
          return job
docs: Mark the job as requested for canceling. Does not actually try to cancel a running job.
  
          :param job_id: the job to be marked as canceling.
          :return: the job object