def test_adjustingWhenPoolStopped(self):
        """
        L{ThreadPool.adjustPoolsize} only modifies the pool size and does not
        start new workers while the pool is not running.
        """
        pool = threadpool.ThreadPool(0, 5)
        pool.start()
        pool.stop()
        pool.adjustPoolsize(2)
        self.assertEqual(len(pool.threads), 0)

        L{ThreadPool.adjustPoolsize} only modifies the pool size and does not
        start new workers while the pool is not running.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_threadpool.py