}

func (h *handlers) hasAny(id HandlerID) bool {
	if !id.valid() {
		return false
	}
	return h.single[id] != nil || h.stateless[id] != nil || h.streams[id] != nil
}

func (h *handlers) hasSubhandler(id subHandlerID) bool {
	return h.subSingle[id] != nil || h.subStateless[id] != nil || h.subStreams[id] != nil
}

// RoundTripper provides an interface for type roundtrip serialization.
type RoundTripper interface {