def METHOD_NAME(self):
    previous_unique_together = TestModel._meta.unique_together
    try:
        TestModel._meta.unique_together = []
        errors = TestModel.check()
    finally:
        TestModel._meta.unique_together = previous_unique_together
    self.assertEqual(len(errors), 1)
    self.assertIsInstance(errors[0], checks.Error)
    self.assertEqual(errors[0].id, "wagtailcore.E003")