}
	if msg.Flags&FlagSubroute != 0 {
		if m.subroute == nil {
			return fmt.Errorf("internal error: subroute not defined on client")
		}
		hid := m.subroute.withHandler(msg.Handler)
		before := len(dst)
		dst = append(dst, hid[:]...)
		if debugPrint {
			fmt.Println("Added subroute", hid.String(), "to message", msg, "len", len(dst)-before)
		}
	}
	if msg.Flags&FlagCRCxxh3 != 0 {
		h := xxh3.Hash(dst)

  `I never went to him,' the Mock Turtle said with a sigh:  `he
taught Laughing and Grief, they used to say.'

  `So he did, so he did,' said the Gryphon, sighing in his turn;
and both creatures hid their faces in their paws.

  `And how many hours a day did you do lessons?' said Alice, in a
hurry to change the subject.

  `Ten hours the first day,' said the Mock Turtle: `nine the
next, and so on.'