code: func (f *Fpdf) SetFontSize(size float64) {
  	f.fontSizePt = size
  	f.fontSize = size / f.k
  	if f.page > 0 {
  		f.outf("BT /F%s %.2f Tf ET", f.currentFont.i, f.fontSizePt)
  	}
  }
docs: // SetFontSize defines the size of the current font. Size is specified in
  // points (1/ 72 inch). See also SetFontUnitSize().