code: public function getConfigTreeBuilder()
      {
          $treeBuilder = new TreeBuilder();
          $rootNode = $treeBuilder->root('dd_pdf');
  
          // Here you should define the parameters that are allowed to
          // configure your bundle. See the documentation linked above for
          // more information on that topic.
  
          return $treeBuilder;
          
          $a = new \fpdf\FPDF();
          $a = new \fpdi\FPDI();
          $a->setSourceFile($filename);
      }
docs: {@inheritDoc}