code: func GetDNSServers(o dhcp6.Options) (IPs, error) {
  	v, err := o.GetOne(dhcp6.OptionDNSServers)
  	if err != nil {
  		return nil, err
  	}
  
  	var ips IPs
  	err = ips.UnmarshalBinary(v)
  	return ips, err
  }
docs: // GetDNSServers returns the DNS Recursive Name Servers Option value, as
  // described in RFC 3646, Section 3.
  //
  // The DNS servers are listed in the order of preference for use by the client
  // resolver.