def METHOD_NAME(self, patches):
    patches.mock_open.side_effect = [
        mock.mock_open(read_data='{"test" : "h"}').return_value
    ]
    handler = "dummy_func_model_service"
    with pytest.raises(ValueError, match=r"Expected only one class .*"):
        self.model_loader.load(self.model_name, self.model_dir, handler, 0, 1)