code: func GetIANA(o dhcp6.Options) ([]*IANA, error) {
  	vv, err := o.Get(dhcp6.OptionIANA)
  	if err != nil {
  		return nil, err
  	}
  
  	// Parse each IA_NA value
  	iana := make([]*IANA, len(vv))
  	for i := range vv {
  		iana[i] = &IANA{}
  		if err := iana[i].UnmarshalBinary(vv[i]); err != nil {
  			return nil, err
  		}
  	}
  	return iana, nil
  }
docs: // GetIANA returns the Identity Association for Non-temporary Addresses Option
  // value, as described in RFC 3315, Section 22.4.
  //
  // Multiple IANA values may be present in a single DHCP request.