code: func (o *multiLineOptions) read(rd *bufio.Reader, lineCnt int) {
  	for i := 0; i < lineCnt; i++ {
  		m := plainOptions{}
  		cnt := rd.ReadInt16()
  		m.read(rd, int(cnt))
  		*o = append(*o, m)
  	}
  }
docs: //pointer: append multiLineOptions itself