def _on_request_token(self, authorize_url, callback_uri, callback,
                          response):
        if response.error:
            raise Exception("Could not get request token: %s" % response.error)
        request_token = _oauth_parse_response(response.body)
        data = (base64.b64encode(escape.utf8(request_token["key"])) + b"|" +
                base64.b64encode(escape.utf8(request_token["secret"])))
        self.set_cookie("_oauth_request_token", data)
        args = dict(oauth_token=request_token["key"])
        if callback_uri == "oob":
            self.finish(authorize_url + "?" + urllib_parse.urlencode(args))
            callback()
            return
        elif callback_uri:
            args["oauth_callback"] = urlparse.urljoin(
                self.request.full_url(), callback_uri)
        self.redirect(authorize_url + "?" + urllib_parse.urlencode(args))
        callback()
dataset/ETHPy150Open D-L/SimpleBookMarks/src/tornado/auth.py/OAuthMixin._on_request_token/original