docs: def parse_url(url):
      """ Takes a URL string and returns its protocol and server """
      # Verify that the protocol makes sense.  We shouldn't guess!
      if not RE_PROTOCOL_SERVER.match(url):
          raise Exception("URL should begin with `protocol://domain`")
  
      protocol, server, path, _, _, _ = urlparse.urlparse(url)
  
      return protocol, server