<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _check_for_cancel(self, job_id, current_stage=""):
 """ Check if a job has been requested to be cancelled. When called, the calling function can optionally give the stage it is currently in, so the user has information on where the job was before it was cancelled. :param job_id: The job_id to check :param current_stage: Where the job currently is :return: raises a CancelledError if we find out that we were cancelled. """


        future = self.future_job_mapping[job_id]
        is_cancelled = future._state in [CANCELLED, CANCELLED_AND_NOTIFIED]

        if is_cancelled:
            raise UserCancelledError(last_stage=current_stage)