code: func (r *Reader) ReadInt16() int16 {
  	if r.err != nil {
  		return 0
  	}
  	var n int
  	n, r.err = io.ReadFull(r.rd, r.b[:2])
  	r.cnt += n
  	if r.err != nil {
  		return 0
  	}
  	return int16(binary.LittleEndian.Uint16(r.b[:2]))
  }
docs: // ReadInt16 reads and returns an int16.