protected function gernerate_pdf($html)
    {
        $dompdf = new Dompdf();
        $dompdf->loadHtml($html);
        $dompdf->setPaper('A4', 'portrait');
        $dompdf->set_option("compressed", true);
        $dompdf->set_option('defaultFont', 'sans-serif');
        $dompdf->set_option('isHtml5ParserEnabled', true);
        return $dompdf;
    }