def test_nativeASCII(self):
        """
        Native strings with ASCII code points are unchanged.

        On Python 2, this verifies that ASCII-only byte strings are accepted,
        whereas for Python 3 it is identical to L{test_unicodeASCII}.
        """
        result = _coercedUnicode('text')
        self.assertEqual(result, u'text')
        self.assertIsInstance(result, unicodeCompat)

        Native strings with ASCII code points are unchanged.

        On Python 2, this verifies that ASCII-only byte strings are accepted,
        whereas for Python 3 it is identical to L{test_unicodeASCII}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_compat.py