def workers(self):
        """
        For legacy compatibility purposes, return a total number of workers.

        @return: the current number of workers, both idle and busy (but not
            those that have been quit by L{ThreadPool.adjustPoolsize})
        @rtype: L{int}
        """
        stats = self._team.statistics()
        return stats.idleWorkerCount + stats.busyWorkerCount

        For legacy compatibility purposes, return a total number of workers.

        @return: the current number of workers, both idle and busy (but not
            those that have been quit by L{ThreadPool.adjustPoolsize})
        @rtype: L{int}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/threadpool.py