public function formatURI($type, $id, $uriType = self::SCHEME_TYPE)
    {
        switch ($uriType) {
            case self::SCHEME_TYPE:
                return 'entity://' . $type . '/' . $id;
            case self::STACHE_TYPE:
                return '{{' . $type . '/' . $id . '}}';
        }
        throw new \InvalidArgumentException(sprintf("%s: invalid URI type", $uriType));
    }