def test_errorPageRendering(self):
        """
        L{ErrorPage.render} returns a C{bytes} describing the error defined by
        the response code and message passed to L{ErrorPage.__init__}.  It also
        uses that response code to set the response code on the L{Request}
        passed in.
        """
        code = 321
        brief = "brief description text"
        detail = "much longer text might go here"
        page = self.errorPage(code, brief, detail)
        self._pageRenderingTest(page, code, brief, detail)

        L{ErrorPage.render} returns a C{bytes} describing the error defined by
        the response code and message passed to L{ErrorPage.__init__}.  It also
        uses that response code to set the response code on the L{Request}
        passed in.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_resource.py