def test_fancybasename(self):
        """
        If C{fancybasename} is present, C{__str__} uses it instead of the class name.
        """
        class Foo(util.FancyStrMixin):
            fancybasename = "Bar"
        self.assertEqual(str(Foo()), "<Bar>")

        If C{fancybasename} is present, C{__str__} uses it instead of the class name.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_util.py