public function contentOverview()
 {
     // Table Header
     $header = array('id' => array('data' => t('Id')), 'file_name' => array('data' => t('File Name')), 'content_type' => array('data' => t('Content Type')), 'operations' => array('data' => t('Delete')));
     $rows = array();
     $count = 1;
     foreach (ManageStorage::getAll() as $key => $content) {
         $file = file_load($content->fid);
         $file_link = '';
         if ($file !== NULL) {
             $file_name_value = $file->filename->getvalue();
             $file_name_part = explode('.', $file_name_value[0]['value']);
             $file_name = $file_name_part[0];
             $file_uri = $file->uri->getvalue();
             $file_link = \Drupal::l(t($file_name), Url::fromUri(file_create_url($file_uri[0]['value'])));
         }
         $rows[$key] = array('data' => array($count, $file_link, $content->content_type, \Drupal::l(t('Delete'), Url::fromRoute('node_csv_uploader.delete', ['id' => $content->id]))));
         $count++;
     }
     $table = array('#type' => 'table', '#header' => $header, '#rows' => $rows, '#attributes' => array('id' => 'upload-node-csv'), '#empty' => $this->t('No uploaded csv file available.'));
     return $table;
 }