code: def _job_completed(self, job_name, success, message):
          
          job = self._objects[job_name][Interface['Job']]
          action = self._action_by_operation.get(job['Operation'])
          if not action:
              return
          # We only handle events, which are associated to exactly one object:
          object_path, = job['Objects']
          device = self[object_path]
          if success:
              # It rarely happens, but sometimes UDisks posts the
              # Job.Completed event before PropertiesChanged, so we have to
              # check if the operation has been carried out yet:
              if self._check_action_success[action](device):
                  event_name = self._event_by_action[action]
                  self.trigger(event_name, device)
          else:
              self.trigger('job_failed', device, action, message)
docs: Internal method.
  
          Called when a job of a long running task completes.