code: func (f *Fpdf) SubWrite(ht float64, str string, subFontSize, subOffset float64, link int, linkStr string) {
  	if f.err != nil {
  		return
  	}
  	// resize font
  	subFontSizeOld := f.fontSizePt
  	f.SetFontSize(subFontSize)
  	// reposition y
  	subOffset = (((subFontSize - subFontSizeOld) / f.k) * 0.3) + (subOffset / f.k)
  	subX := f.x
  	subY := f.y
  	f.SetXY(subX, subY-subOffset)
  	//Output text
  	f.write(ht, str, link, linkStr)
  	// restore y position
  	subX = f.x
  	subY = f.y
  	f.SetXY(subX, subY+subOffset)
  	// restore font size
  	f.SetFontSize(subFontSizeOld)
  }
docs: // Adapted from http://www.fpdf.org/en/script/script61.php by Wirus and released with the FPDF license.
  // SubWrite prints text from the current position in the same way as Write().
  // ht is the line height in the unit of measure specified in New(). str
  // specifies the text to write. subFontSize is the size of the font in points.
  // subOffset is the vertical offset of the text in points; a positive value
  // indicates a superscript, a negative value indicates a subscript. link is the
  // identifier returned by AddLink() or 0 for no internal link. linkStr is a
  // target URL or empty for no external link. A non--zero value for link takes
  // precedence over linkStr.
  //
  // The SubWrite example demonstrates this method.