def test_update_custom_validation(self):
        """
        REST Api: Test update item custom validation
        """
        client = self.app.test_client()
        token = self.login(client, USERNAME_ADMIN, PASSWORD_ADMIN)
        with model1_data(self.appbuilder.session, 3):
            model1 = (
                self.appbuilder.get_session.query(Model1)
                .filter_by(field_string="test2")
                .one_or_none()
            )
            model_id = model1.id
            item = dict(field_string="test_Put", field_integer=0, field_float=0.0)
            uri = f"api/v1/model1customvalidationapi/{model_id}"
            rv = self.auth_client_put(client, token, uri, item)
            self.assertEqual(rv.status_code, 422)
            item = dict(field_string="Atest_Put", field_integer=0, field_float=0.0)
            uri = f"api/v1/model1customvalidationapi/{model_id}"
            rv = self.auth_client_put(client, token, uri, item)
            self.assertEqual(rv.status_code, 200)

        REST Api: Test update item custom validation
        
tests/test_api.py