code: func brokerEntrySeemsValid(broker string) bool {
  	if !strings.Contains(broker, ":") {
  		return false
  	}
  
  	parts := strings.Split(broker, ":")
  	if len(parts) > 2 {
  		return false
  	}
  
  	host := parts[0]
  	port := parts[1]
  
  	if _, err := strconv.ParseUint(port, 10, 16); err != nil {
  		return false
  	}
  
  	// Valid hostnames may contain only the ASCII letters 'a' through 'z' (in a
  	// case-insensitive manner), the digits '0' through '9', and the hyphen. IP
  	// v4 addresses are  represented in dot-decimal notation, which consists of
  	// four decimal numbers, each ranging from 0 to 255, separated by dots,
  	// e.g., 172.16.254.1
  	// The following regular expression:
  	// 1. allows just a-z (case-insensitive), 0-9, and the dot and hyphen characters
  	// 2. does not allow leading trailing dots or hyphens
  	re, _ := regexp.Compile("^([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9.-]*[a-zA-Z0-9])$")
  	matched := re.FindString(host)
  	return len(matched) == len(host)
  }
docs: // This does just a barebones sanity check.