def METHOD_NAME(s3_mock: S3Path) -> None:
    backend = s3.S3Storage()
    with backend.update_safe(
        f"/{s3_mock.bucket}/todo", mode="w+", encoding="utf-8"
    ) as fp:
        fp.write("flask\n")
    assert s3.S3Path(f"/{s3_mock.bucket}/todo").read_text() == "flask\n"