def METHOD_NAME(self):
    tag = self._force_tag(get_random_string(12) + " " + get_random_string(12))
    self._login("inventory.add_tag")
    response = self.client.post(reverse("inventory:create_tag"),
                                {"name": tag.name.replace(" ", "-")})
    self.assertEqual(response.status_code, 200)
    self.assertTemplateUsed(response, "inventory/tag_form.html")
    self.assertFormError(response.context["form"], "name", "A tag with a conflicting slug already exists.")