code: function(data, algorithm) {
      if (arguments.length === 1) {
        algorithm = 'md5';
      }
      return crypto.createHash(algorithm).update(data).digest('hex');
    }
docs: /*
  `string.hash(file, [algorithm], callback)`
  ------------------------------------------
  Output the hash of a supplied string in hexadecimal
  form. The default algorithm to compute the hash is md5.