public static function load($param) {
        global $DB;
        if (is_object($param)) {
            $event = new calendar_event($param);
        } else {
            $event = $DB->get_record('event', array('id' => (int)$param), '*', MUST_EXIST);
            $event = new calendar_event($event);
        }
        return $event;
    }