title: Merge pdfs documents in one KnpLabs/KnpSnappyBundle
body: <p>I'm trying to use KnpLabs/KnpSnappyBundle, I want to know if i can :</p>
  
  <ol>
  <li>Merge pdf files in one</li>
  <li>Convert images to pdf</li>
  <li>Load pdf locally</li>
  </ol>
  
  <p>My Controller</p>
  
  <pre><code>&lt;?php
  
  namespace App\Controller;
  
  use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
  use Symfony\Component\Routing\Annotation\Route;
  use Knp\Snappy\Pdf;
  use Symfony\Component\HttpKernel\KernelInterface;
  
  class PdfController extends AbstractController
  {
      private $pdf;
      private $kernel;
  
      public function __construct(Pdf $pdf, KernelInterface $kernel)
      {
          $this-&gt;pdf = $pdf;
          $this-&gt;kernel = $kernel;
      }
  
      /**
       * @Route("pdf")
       */
      public function pdfAction()
      {
          $html = "&lt;html&gt;&lt;body&gt;hello snappy !&lt;/body&gt;&lt;/html&gt;";
          // trying to merge pdf -&gt; error
          $this-&gt;pdf-&gt;generate(['http://www.pdf995.com/samples/pdf.pdf', 'http://www.africau.edu/images/default/sample.pdf'], 'merge.pdf');
          //trying to convert jpg to pdf -&gt; it show empty PDF !
          $this-&gt;pdf-&gt;generate('https://www.cleverfiles.com/howto/wp-content/uploads/2018/03/minion.jpg', 'jpgToPdf.pdf');
      }
  }
  </code></pre>
  
  <p>Error :</p>
  
  <blockquote>
    <p>The exit status code '1' says something went wrong: stderr: "Loading
    pages (1/6) [> ] 0% [===> ] 5% [======> ] 10% Error: Failed loading
    page <a href="http://www.pdf995.com/samples/pdf.pdf" rel="nofollow noreferrer">http://www.pdf995.com/samples/pdf.pdf</a> (sometimes it will work
    just to ignore this error with --load-error-handling ignore) Error:
    Failed loading page <a href="http://www.africau.edu/images/default/sample.pdf" rel="nofollow noreferrer">http://www.africau.edu/images/default/sample.pdf</a>
    (sometimes it will work just to ignore this error with
    --load-error-handling ignore) Exit with code 1, due to unknown error. " stdout: "" command: /usr/bin/wkhtmltopdf --lowquality
    '<a href="http://www.pdf995.com/samples/pdf.pdf" rel="nofollow noreferrer">http://www.pdf995.com/samples/pdf.pdf</a>'
    '<a href="http://www.africau.edu/images/default/sample.pdf" rel="nofollow noreferrer">http://www.africau.edu/images/default/sample.pdf</a>' 'merge.pdf'.</p>
  </blockquote>