/**
  * Makes the pdf use some other pdf as a template
  *
  * @param $strFilename string The filename including the path without TL_ROOT
  *
  * @throws \MpdfException
  */
 public function addTemplatePdf($strFilename)
 {
     $this->objPdf->setHeaderTemplate(TL_ROOT . '/' . ltrim($strFilename, '/'));
 }