// Handle ACKs for the different protocol levels.
func HandleAck(c *stompngo.Connection, h stompngo.Headers, id string) {
	ah := stompngo.Headers{}
	//
	switch c.Protocol() {
	case stompngo.SPL_12:
		ah = ah.Add("id", h.Value("ack"))
	case stompngo.SPL_11:
		ah = ah.Add("message-id", h.Value("message-id")).Add("subscription", id)
	case stompngo.SPL_10:
		ah = ah.Add("message-id", h.Value("message-id"))
	default:
		llu.Fatalf("v1:%v v2:%v\n", "ack invalid protocol level, should not happen")
	}
	if cv, ok := h.Contains(stompngo.HK_RECEIPT); ok {
		ah = ah.Add(stompngo.HK_RECEIPT, cv)
	}
	e := c.Ack(ah)
	if e != nil {
		llu.Fatalf("v1:%v v2:%v v3:%v\n", "ack failed", e, c.Protocol())
	}
	return
}