code: def report_status(self, status):
          
          status = Instance('', TaskStatus).validate(None, status)
          print(r'{taskname} | {percent:>3}% | {message}'.format(
              taskname=self.__class__.__name__,
              percent=int(round(100*status.progress)),
              message=status.message if status.message else '',
          ))
docs: Hook for reporting the task status towards completion