def test_minimalWorker(self):
        """
        L{DistTrialRunner} doesn't try to start more workers than the number of
        tests.
        """
        workers = []
        fakeReactor = CountingReactor(workers)
        self.addCleanup(self.reap, workers)

        self.runner.run(TestCase(), fakeReactor)
        self.assertEqual(fakeReactor.runCount, 1)
        self.assertEqual(fakeReactor.spawnCount, 1)

        L{DistTrialRunner} doesn't try to start more workers than the number of
        tests.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/_dist/test/test_disttrial.py