async def METHOD_NAME(
    bucket_fs: BucketFS, mock_bucket_provider: MockBucketProvider
) -> None:
    assert await bucket_fs.is_dir(PurePosixPath("/"))
    assert await bucket_fs.is_dir(PurePosixPath(""))
    await mock_bucket_provider.put_blob("some_key/foo", b"data")
    await mock_bucket_provider.put_blob("some_key/bar/", b"")
    assert await bucket_fs.is_dir(PurePosixPath("some_key"))
    assert await bucket_fs.is_dir(PurePosixPath("some_key/bar"))
    assert not await bucket_fs.is_dir(PurePosixPath("some_key/foo"))