}

	if len(subroute) == 0 {
		if m.handlers.hasAny(id) && !id.isTestHandler() {
			return fmt.Errorf("handler %v: %w", id.String(), ErrHandlerAlreadyExists)
		}

		m.handlers.single[id] = h
		return nil
	}
	subID := makeSubHandlerID(id, s)
	if m.handlers.hasSubhandler(subID) && !id.isTestHandler() {
		return fmt.Errorf("handler %v, subroute:%v: %w", id.String(), s, ErrHandlerAlreadyExists)
	}

		panic(fmt.Sprintf("out of handler IDs. %d > %d", handlerLast, 255))
	}
}

func (h HandlerID) valid() bool {
	return h != handlerInvalid && h < handlerLast
}

func (h HandlerID) isTestHandler() bool {
	return h >= handlerTest && h <= handlerTest2
}

// RemoteErr is a remote error type.
// Any error seen on a remote will be returned like this.
type RemoteErr string