          self.gipsy_book.save()
  
      def get_changelist(self, request, model, modeladmin):
          return ChangeList(request, model, modeladmin.list_display, modeladmin.list_display_links,
              modeladmin.list_filter, modeladmin.date_hierarchy, modeladmin.search_fields,
              modeladmin.list_select_related, modeladmin.list_per_page, modeladmin.list_max_show_all, modeladmin.list_editable, modeladmin)
  
 
</s> remove         self.assertEqual(list(queryset), [john])
 </s> add         self.assertEqual(list(queryset), [self.john]) </s> remove         self.assertEqual(list(queryset), [jack, john])
 </s> add         self.assertEqual(list(queryset), [self.jack, self.john]) </s> remove         dev = Department.objects.create(code='DEV', description='Development')
        design = Department.objects.create(code='DSN', description='Design')
        john = Employee.objects.create(name='John Blue', department=dev)
        jack = Employee.objects.create(name='Jack Red', department=design)

 </s> add 
        # Departments
        self.dev = Department.objects.create(code='DEV', description='Development')
        self.design = Department.objects.create(code='DSN', description='Design')

        # Employees
        self.john = Employee.objects.create(name='John Blue', department=self.dev)
        self.jack = Employee.objects.create(name='Jack Red', department=self.design)

          self.gipsy_book.save()
  
        # Departments
        self.dev = Department.objects.create(code='DEV', description='Development')
        self.design = Department.objects.create(code='DSN', description='Design')

        # Employees
        self.john = Employee.objects.create(name='John Blue', department=self.dev)
        self.jack = Employee.objects.create(name='Jack Red', department=self.design)

      def get_changelist(self, request, model, modeladmin):
          return ChangeList(request, model, modeladmin.list_display, modeladmin.list_display_links,
              modeladmin.list_filter, modeladmin.date_hierarchy, modeladmin.search_fields,
              modeladmin.list_select_related, modeladmin.list_per_page, modeladmin.list_max_show_all, modeladmin.list_editable, modeladmin)
  
keep add keep keep keep keep keep
 Fixed #19318 -- Ensured that the admin's SimpleListFilter options can be displayed as selected even if the lookup's first element is not a string. 
tests/regressiontests/admin_filters/tests.py