docs: def formdata_post(url, fields):
      """Send an HTTP request with a multipart/form-data body for the
      given URL and return the data returned by the server.
      """
      content_type, data = formdata_encode(fields)
      req = urllib2.Request(url, data)
      req.add_header('Content-Type', content_type)
      return urllib2.urlopen(req).read()