void OnNotify(string code, string[] users)
 {
     if (!string.IsNullOrEmpty(code))
     {
         var args = new RtGroupNotifyEventArgs()
         {
             Code = code
         };
         if (users != null && users.Length > 0)
         {
             foreach (var u in users)
             {
                 args.Users.Add(u);
             }
         }
         this.GroupNotifyEvent?.Invoke(this, args);
     }
 }
 private static void RtService_GroupNotifyEvent(object sender, RtGroupNotifyEventArgs e)
 {
     _handler.GroupNotifyHandler?.Invoke(e.Code, e.Users);
 }