【Unity】UnityWebRequest でブラウザキャッシュを無効にする

private static UnityWebRequest SetupUnityWebRequest(string _url)
{
    UnityWebRequest wr = UnityWebRequest.Get(_url);
    wr.SetRequestHeader("Cache-Control", "no-cache, no-store, must-revalidate");
    wr.SetRequestHeader("Pragma", "no-cache");
    wr.SetRequestHeader("Expires", "0");
    return wr;
}