code: func (b *NexthopRegisterBody) Serialize(version uint8) ([]byte, error) {
  	buf := make([]byte, 0)
  
  	// List of Registered Nexthops
  	for _, nh := range b.Nexthops {
  		nhBuf, err := nh.Serialize()
  		if err != nil {
  			return nil, err
  		}
  		buf = append(buf, nhBuf...)
  	}
  
  	return buf, nil
  }
docs: // Reference: sendmsg_nexthop in bgpd/bgp_nht.c of Quagga1.2.x (ZAPI3)
  // Reference: sendmsg_zebra_rnh in bgpd/bgp_nht.c of FRR3.x (ZAPI4)
  // Reference: zclient_send_rnh function in lib/zclient.c of FRR5.x (ZAPI5)