code: def field_names(self, admin_model):
          
          request = FakeRequest(user=self.admin_user)
          return admin_model.get_list_display(request)
docs: Returns the names of the fields/columns used by the given admin
          model.
  
          :param admin_model:
              Instance of a :class:`admin.ModelAdmin` object that is responsible
              for displaying the change list
          :returns:
              List of field names