Call get rich menu list API.

        https://developers.line.me/en/docs/messaging-api/reference/#get-rich-menu-list

        :param timeout: (optional) How long to wait for the server
            to send data before giving up, as a float,
            or a (connect timeout, read timeout) float tuple.
            Default is self.http_client.timeout
        :type timeout: float | tuple(float, float)
        :rtype: list(T <= :py:class:`linebot.models.reponse.RichMenuResponse`)
        :return: list[RichMenuResponse] instance

def get_rich_menu_list(self, timeout=None):
        """Call get rich menu list API.

        https://developers.line.me/en/docs/messaging-api/reference/#get-rich-menu-list

        :param timeout: (optional) How long to wait for the server
            to send data before giving up, as a float,
            or a (connect timeout, read timeout) float tuple.
            Default is self.http_client.timeout
        :type timeout: float | tuple(float, float)
        :rtype: list(T <= :py:class:`linebot.models.reponse.RichMenuResponse`)
        :return: list[RichMenuResponse] instance
        """
        response = self._get(
            '/v2/bot/richmenu/list',
            timeout=timeout
        )

        result = []
        for richmenu in response.json['richmenus']:
            result.append(RichMenuResponse.new_from_json_dict(richmenu))

        return result