def _get_sorting_message(request, key):
        control_list = []
        reverse = request.url.query.get('reverse', None)
        if reverse is None:
            return control_list
        if reverse.lower() == "":
            control_list.append(client_list_control_pb2.ClientSortControls(
                reverse=True,
                keys=key.split(",")
            ))
        elif reverse.lower() != 'false':
            control_list.append(client_list_control_pb2.ClientSortControls(
                reverse=True,
                keys=reverse.split(",")
            ))
        return control_list