def test_missingTemplateLoader(self):
        """
        L{Element.render} raises L{MissingTemplateLoader} if the C{loader}
        attribute is L{None}.
        """
        element = Element()
        err = self.assertRaises(MissingTemplateLoader, element.render, None)
        self.assertIdentical(err.element, element)

        L{Element.render} raises L{MissingTemplateLoader} if the C{loader}
        attribute is L{None}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_template.py