def test_UnicodeInstantiationUnicodePreauthChild(self):
        """
        Calling L{FilePath.preauthChild} on a text-mode L{FilePath} with a text
        subpath will return a text-mode FilePath.
        """
        fp = filepath.FilePath(u'./parent-mon\u20acy')
        child = fp.preauthChild(u'mon\u20acy')
        self.assertEqual(type(child.path), unicode)

        Calling L{FilePath.preauthChild} on a text-mode L{FilePath} with a text
        subpath will return a text-mode FilePath.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_paths.py