function decodefield (str) {
  var match = EXT_VALUE_REGEXP.exec(str);

  if (!match) {
    throw new TypeError('invalid extended field value')
  }

  var charset = match[1].toLowerCase();
  var encoded = match[2];
  var value;

  // to binary string
  var binary = encoded.replace(HEX_ESCAPE_REPLACE_REGEXP, pdecode);

  switch (charset) {
    case 'iso-8859-1':
      value = getlatin1(binary);
      break
    case 'utf-8':
      value = Buffer$2.from(binary, 'binary').toString('utf8');
      break
    default:
      throw new TypeError('unsupported charset in extended field')
  }

  return value
}
Proxy to the app `Router#route()`
Returns a new `Route` instance for the _path_.

Routes are isolated middleware stacks for specific paths.
See the Route api docs for details.

@public