/// <summary>
 /// 推播通知目的地
 /// </summary>
 /// <param name="contents">通知內容清單</param>
 protected void PushDestination(List <PushContent> contents)
 {
     _destinations.ForEach(destination =>
     {
         var pusher = PusherFactory.CreateInstance(destination);
         contents.ForEach(content => pusher.Push(content));
     });
 }