private function addDocumentForm($form, $document)
 {
     $database = new DBConnection($this->app);
     if (is_string($document)) {
         $qb = $document;
     } elseif (is_numeric($document)) {
         $qb = $database->findDocumentNameById($document);
     } else {
         $qb = $database->findAllDocuments();
     }
     $form->add($this->factory->createNamed('files', 'choice', null, array('empty_value' => 'Empty', 'auto_initialize' => false, 'choices' => ['Files' => $qb])));
     /*$form->add($this->factory->createNamed('files', 'choice', null, [
           'choices' => ['Files' => $document],
           'label' => 'Files',
       ]));*/
 }