code: func getDefaultAddresses(bindAddress string) (defaultHealthzAddress, defaultMetricsAddress string) {
  	if net.ParseIP(bindAddress).To4() != nil {
  		return "0.0.0.0", "127.0.0.1"
  	}
  	return "[::]", "[::1]"
  }
docs: // getDefaultAddresses returns default address of healthz and metrics server
  // based on the given bind address. IPv6 addresses are enclosed in square
  // brackets for appending port.