Phalcon\Db\Adapter\MongoDB\GridFS\Bucket::rename PHP Method

    public function rename($id, $newFilename)
    {
        $updateResult = $this->collectionWrapper->updateFilenameForId($id, $newFilename);
        if ($updateResult->getModifiedCount() === 1) {
            return;
        }
        /* If the update resulted in no modification, it's possible that the
         * file did not exist, in which case we must raise an error. Checking
         * the write result's matched count will be most efficient, but fall
         * back to a findOne operation if necessary (i.e. legacy writes).
         */
        $found = $updateResult->getMatchedCount() !== null ? $updateResult->getMatchedCount() === 1 : $this->collectionWrapper->findFileById($id) !== null;
        if (!$found) {
            throw FileNotFoundException::byId($id, $this->getFilesNamespace());
        }
    }