async def METHOD_NAME(
    mirror: BandersnatchMirror, monkeypatch: MonkeyPatch
) -> None:
    master = mirror.master
    url_fetch_404 = AsyncMock(
        side_effect=ClientResponseError(status=404, history=(), request_info=None)
    )
    monkeypatch.setattr(master, "url_fetch", url_fetch_404)
    package_simple_dir = mirror.webdir / "simple" / "cooper"
    package_simple_dir.mkdir()
    index_page = package_simple_dir / "index.html"
    index_page.touch()
    assert index_page.exists()
    args = _fake_args()
    args.dry_run = False
    config = _fake_config()
    config["mirror"]["directory"] = str(mirror.homedir)
    assert await delete_packages(config, args, master) == 0
    assert not index_page.exists()
    assert not package_simple_dir.exists()