code: func (w *Writer) WriteZeroes(cnt int) {
  	if w.err != nil {
  		return
  	}
  
  	// zero out scratch area
  	l := cnt
  	if l > len(w.b) {
  		l = len(w.b)
  	}
  	for i := 0; i < l; i++ {
  		w.b[i] = 0
  	}
  
  	for i := 0; i < cnt; {
  		j := cnt - i
  		if j > len(w.b) {
  			j = len(w.b)
  		}
  		n, _ := w.wr.Write(w.b[:j])
  		if n != j {
  			return
  		}
  		i += n
  	}
  }
docs: // WriteZeroes writes cnt zero byte values.