def assertIsPoll(self, install):
        """
        Assert the given function will install the poll() reactor, or select()
        if poll() is unavailable.
        """
        if hasattr(select, "poll"):
            self.assertEqual(
                install.__module__, 'twisted.internet.pollreactor')
        else:
            self.assertEqual(
                install.__module__, 'twisted.internet.selectreactor')

        Assert the given function will install the poll() reactor, or select()
        if poll() is unavailable.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_default.py