def test_preserve_links(self):
        """Test submission when the links are not changed."""
        form_data = self._base_form()
        links = ExternalLink.objects.all()
        form_data.update(_build_links(2, *map(_form_from_link, links)))
        response = self.client.post(self.edit_path, form_data)
        self.assertRedirects(response, self.view_path)
        eq_(ExternalLink.objects.count(), 2)