code: func KeyValue(label string) (key string, value string) {
  	if kv := strings.SplitN(label, "=", 2); len(kv) > 0 {
  		key = kv[0]
  		if len(kv) > 1 {
  			value = kv[1]
  		}
  	}
  	return
  }
docs: // KeyValue decomposes the label in the (key,value) pair