def test_unicodeParent(self):
        """
        Calling C{parent} on a text-mode L{FilePath} will return a text-mode
        L{FilePath}.
        """
        fp = filepath.FilePath(u"./")
        parent = fp.parent()
        self.assertIsInstance(parent.path, unicode)

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