code: func WriteIndentedN(w io.Writer, b []byte, n int) error {
  	s := bufio.NewScanner(bytes.NewReader(b))
  	if !s.Scan() {
  		return nil
  	}
  	l := s.Text()
  	for {
  		for x := 0; x < n; x++ {
  			if _, err := fmt.Fprint(w, " "); err != nil {
  				return err
  			}
  		}
  		if _, err := fmt.Fprint(w, l); err != nil {
  			return err
  		}
  		if !s.Scan() {
  			break
  		}
  		l = s.Text()
  		if _, err := fmt.Fprint(w, "\n"); err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // WriteIndentedN indents all lines n spaces.