function setCookie (headers, cookie) {
  webidl.argumentLengthCheck(arguments, 2, 'setCookie')

  brandChecks(headers)

  cookie = webidl.converters.Cookie(cookie)

  const str = stringify(cookie)

  if (str) {
    headers.append('set-cookie', str, true)
  }
}
@param {Headers} headers
@param {Cookie} cookie
@returns {void}