def METHOD_NAME(
    self, decorators: str
) -> None:
    module = astroid.parse(
        decorators
        + """
    @Unsubscriptable
    @Subscriptable
    def decorated():
        ...
    test = decorated[None]
    """
    )
    subscript = module.body[-1].value
    with self.assertAddsMessages(
        MessageTest(
            "unsubscriptable-object",
            node=subscript.value,
            args="decorated",
            confidence=UNDEFINED,
            line=18,
            col_offset=7,
            end_line=18,
            end_col_offset=16,
        )
    ):
        self.checker.visit_subscript(subscript)