code: func main() {
  	hosts := map[string]IPAddr{
  		"loopback":  {127, 0, 0, 1},
  		"googleDNS": {8, 8, 8, 8},
  	}
  	for name, ip := range hosts {
  		fmt.Printf("%v: %v\n", name, ip)
  	}
  }
docs: // TODO: Add a "String() string" method to IPAddr.