def test_proxy_can_access_stream_attrs(self, stream):
        """``SpooledTemporaryFile`` doesn't implement some of
        ``IOBase``. Ensure that ``FileStorage`` can still access the
        attributes from the backing file object.

        https://github.com/pallets/werkzeug/issues/1344
        https://github.com/python/cpython/pull/3249
        """
        file_storage = self.storage_class(stream=stream())

        for name in ("fileno", "writable", "readable", "seekable"):
            assert hasattr(file_storage, name)

        file_storage.close()
``SpooledTemporaryFile`` doesn't implement some of
        ``IOBase``. Ensure that ``FileStorage`` can still access the
        attributes from the backing file object.

        https://github.com/pallets/werkzeug/issues/1344
        https://github.com/python/cpython/pull/3249
        
tests/test_datastructures.py