def METHOD_NAME(self):
    test_page = buyersguide_factories.BuyersGuidePageFactory()
    form = self.form_class(
        data=({"title": "Test CTA", "link_target_page": test_page}),
    )
    self.assertFalse(form.is_valid())
    self.assertEqual(1, len(form.errors))
    self.assertIn("link_label", form.errors)