ipv4 static method
Generate a random IPv4 address. This address is entirely randomized, so there is no guarantee that it is a valid address.
Implementation
static String ipv4() {
var x = '';
for (var i = 0; i < 4; x += '.') {
x += '${random.nextInt(256)}';
i++;
}
return x.substring(0, x.length - 1);
}