docs: def tablib_export_action(modeladmin, request, queryset, file_type="xls"):
      """
      Allow the user to download the current filtered list of items
  
      :param file_type:
          One of the formats supported by tablib (e.g. "xls", "csv", "html",
          etc.)
      """
  
      dataset = SimpleDataset(queryset, headers=None)
      filename = '{0}.{1}'.format(
          smart_str(modeladmin.model._meta.verbose_name_plural), file_type)
  
      response_kwargs = {
          'content_type': get_content_type(file_type)
      }
  
      response = HttpResponse(getattr(dataset, file_type), **response_kwargs)
      response['Content-Disposition'] = 'attachment; filename={0}'.format(
          filename)
      return response