public function getNameById($id, $default = null)
    {
        $keyMap = $this->getHandler()->getKeyMap();
        if (empty($keyMap)) {
            return $default;
        }
        foreach ($keyMap as $name => $value) {
            if (isset($value['id']) && $value['id'] == $id) {
                return $name;
            }
        }
        return $default;
    }