provider=method,
                    error_msg=message % response.status,
                )

            return parse_grants_response(response.data)

        def parse_grants_response(data):
            """
            Parser for AssumeRoleWithClientGrants response

            :param data: Response data for AssumeRoleWithClientGrants request
            :return: dict
            """

    @classmethod
    def fromstring(cls, root_name, data):
        """Initialize STSElement from name and XML string data.

        :param name: Name for XML data. Used in XML errors.
        :param data: string data to be parsed.
        :return: Returns an STSElement.
        """
        try:
            return cls(root_name, cElementTree.fromstring(data))
        except _ETREE_EXCEPTIONS as error:
            raise InvalidXMLError(

              "response_type": "code",
              "state": state,
              "redirect_uri": callback_uri,
              "scope": "openid"}

    url = authorize_url + "?" + urllib.parse.urlencode(params)
    return url


@app.route('/oauth2/callback')
def callback():
    error = request.args.get('error', '')
    if error:
        return "Error: " + error