def METHOD_NAME(self) -> None:
    code = """
    import attr
    @attr.s
    class Foo:
        bar: int = attr.ib(default=5)
    Foo()
    """
    should_be_unknown = next(astroid.extract_node(code).infer()).getattr("bar")[0]
    self.assertIsInstance(should_be_unknown, astroid.Unknown)