public static function available_methods($includenone = true) {

        if ($includenone) {
            $list = array('' => get_string('gradingmethodnone', 'core_grading'));
        } else {
            $list = array();
        }

        foreach (core_component::get_plugin_list('gradingform') as $name => $location) {
            $list[$name] = get_string('pluginname', 'gradingform_'.$name);
        }

        return $list;
    }