def test_tooMuchWorkBeforeStarting(self):
        """
        If the amount of work before starting exceeds the maximum number of
        threads allowed to the threadpool, only the maximum count will be
        started.
        """
        helper = PoolHelper(self, 0, 10)
        n = 50
        for x in range(n):
            helper.threadpool.callInThread(lambda: None)
        helper.performAllCoordination()
        self.assertEqual(helper.workers, [])
        helper.threadpool.start()
        helper.performAllCoordination()
        self.assertEqual(len(helper.workers), helper.threadpool.max)

        If the amount of work before starting exceeds the maximum number of
        threads allowed to the threadpool, only the maximum count will be
        started.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_threadpool.py