code: func (b *GetLabelChunkBody) Serialize(version uint8) ([]byte, error) {
  	buf := make([]byte, 8)
  	pos := 0
  	if version > 4 {
  		buf[pos] = b.Proto
  		binary.BigEndian.PutUint16(buf[pos+1:pos+3], b.Instance)
  		pos += 3
  	}
  	buf[pos] = b.Keep
  	binary.BigEndian.PutUint32(buf[pos+1:pos+5], b.ChunkSize)
  	pos += 5
  	return buf[0:pos], nil
  }
docs: // Reference: zread_get_label_chunk in zebra/zserv.c of FRR3.x
  // Reference: zread_get_label_chunk in zebra/zapi_msg.c of FRR5.x and 6.x