def test_collectNotDefault(self):
        """
        By default, tests should not force garbage collection.
        """
        test = self.BasicTest('test_foo')
        result = reporter.TestResult()
        test.run(result)
        self.assertEqual(self._collectCalled, ['setUp', 'test', 'tearDown'])

        By default, tests should not force garbage collection.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_tests.py