def METHOD_NAME(mock_create_docstring, empty_swagger_spec, pet_spec):
    pet_type = create_model_type(empty_swagger_spec, 'Pet', pet_spec)
    assert mock_create_docstring.call_count == 0
    assert pet_type.__doc__ == mock_create_docstring.return_value
    assert mock_create_docstring.call_count == 1