public function save($path, $signatureAlgo)
    {
        $pos = $this->determineSignatureBegin();

        $algos = array(
            \Phar::MD5 => 'md5',
            \Phar::SHA1 => 'sha1',
            \Phar::SHA256 => 'sha256',
            \Phar::SHA512 => 'sha512',
        );

        if (!isset($algos[$signatureAlgo])) {
            throw new \UnexpectedValueException('Invalid hash algorithm given: '.$signatureAlgo.' expected one of Phar::MD5, Phar::SHA1, Phar::SHA256 or Phar::SHA512');
        }
        $algo = $algos[$signatureAlgo];

        // re-sign phar
        //           signature
        $signature = hash($algo, substr($this->contents, 0, $pos), true)
            // sig type
            . pack('L', $signatureAlgo)
            // ohai Greg & Marcus
            . 'GBMB';

        $this->contents = substr($this->contents, 0, $pos) . $signature;

        return file_put_contents($path, $this->contents);
    }