def add_to_end(self, html, extra_html):
        """
        Adds extra_html to the end of the html page (before </body>)
        """
        match = self._end_body_re.search(html)
        if not match:
            return html % extra_html
        else:
            return html[:match.start()] + extra_html + html[match.start():]
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/webob_0_9/docs/comment-example-code/example.py/Commenter.add_to_end/operator `+` -> `%`