Issue #3281764 by ghost of drupal past, steven jones: Excel batch completely...

      $user_ID = $current_user->isAuthenticated() ? $current_user->id() : NULL;

      $timestamp = \Drupal::time()->getRequestTime();

      $filename = \Drupal::token()->replace($view->getDisplay()->options['filename'], ['view' => $view]);

      $extension = reset($view->getDisplay()->options['style']['options']['formats']);

      $extension = reset($view->getStyle()->options['formats']);

      // Checks if extension is already included in the filename.

      if (!preg_match("/^.*\.($extension)$/i", $filename)) {