def METHOD_NAME(router: Any) -> None:
    folder = pathlib.Path(__file__).parent
    router.add_routes([web.static("/prefix", folder)])
    assert len(router.resources()) == 1  # 2 routes: for HEAD and GET
    resource = list(router.resources())[0]
    info = resource.get_info()
    assert info["prefix"] == "/prefix"
    assert info["directory"] == folder
    url = resource.url_for(filename="aiohttp.png")
    assert url == URL("/prefix/aiohttp.png")