def urlsafe(self):
<EOL>urlsafe = base64.b64encode(self.reference().Encode())<EOL>return urlsafe.rstrip('<STR_LIT:=>').replace('<STR_LIT:+>', '<STR_LIT:->').replace('<STR_LIT:/>', '<STR_LIT:_>')<EOL>
Return a url-safe string encoding this Key's Reference.

        This string is compatible with other APIs and languages and with
        the strings used to represent Keys in GQL and in the App Engine
        Admin Console.