public function grid_start($id = null, $class = null) {
        $gridclass = 'grid-start grid-row-r d-flex flex-wrap row';
        if (is_null($class)) {
            $class = $gridclass;
        } else {
            $class .= ' ' . $gridclass;
        }
        $attributes = array();
        if (!is_null($id)) {
            $attributes['id'] = $id;
        }
        return html_writer::start_div($class, $attributes);
    }