def test_emptyList(self):
        """
        When asked to run an empty list of callables, runSequentially returns a
        successful Deferred that fires an empty list.
        """
        d = util._runSequentially([])
        self.assertDeferredResult(d, self.assertEqual, [])

        When asked to run an empty list of callables, runSequentially returns a
        successful Deferred that fires an empty list.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_util.py