def do_stop_workers(self):
        """Stop all workers

        :return: None
        """
        logger.info("Stopping all workers (%d)", len(self.workers))
        for worker in list(self.workers.values()):
            try:
                logger.info(" - stopping '%s'", worker.get_id())
                worker.terminate()
                worker.join(timeout=1)
                logger.info(" - stopped")
            # A already dead worker or in a worker
            except (AttributeError, AssertionError):
                pass
            except Exception as exp:  # pylint: disable=broad-except
                logger.error("exception: %s", str(exp))
Stop all workers

        :return: None