'An empty patch does not modify anything'

@ddt.data(*AUTH_ATTRS)
def test_empty_patch(self, auth_attr):

    display_name = self.ccx.display_name
    max_students_allowed = self.ccx.max_student_enrollments_allowed
    coach_email = self.ccx.coach.email
    ccx_structure = self.ccx.structure
    resp = self.client.patch(self.detail_url, {}, format='json', HTTP_AUTHORIZATION=getattr(self, auth_attr))
    self.assertEqual(resp.status_code, status.HTTP_204_NO_CONTENT)
    ccx = CustomCourseForEdX.objects.get(id=self.ccx.id)
    self.assertEqual(display_name, ccx.display_name)
    self.assertEqual(max_students_allowed, ccx.max_student_enrollments_allowed)
    self.assertEqual(coach_email, ccx.coach.email)
    self.assertEqual(ccx_structure, ccx.structure)
