public static function available_areas($component) {
        global $CFG;

        list($plugintype, $pluginname) = core_component::normalize_component($component);

        if ($component === 'core_grading') {
            return array();

        } else if ($plugintype === 'mod') {
            return plugin_callback('mod', $pluginname, 'grading', 'areas_list', null, array());

        } else {
            throw new coding_exception('Unsupported area location');
        }
    }