/**
* Draw the ISBN text on barcode.
*
* @param RendererInterface $renderer
*/
protected function drawText(RendererInterface &$renderer)
{
$textHeight = $this->getTextHeight();
$this->options['barheight'] += $textHeight;
parent::drawText($renderer);
$renderer->drawText([$this->getTextX(), $this->getContentOffsetTop() + 1], 'ISBN ' . $this->getISBN(true), $this->options['forecolor'], $this->options['font'], $this->options['fontsize'], 'center');
$this->options['barheight'] -= $textHeight;
}
