public void logout(CometChatFormCallback callback)
 {
     cometchat.Logout(
         (dict) => { if (dict != null && callback != null)
                     {
                         callback.SuccessCallback(dict.ToString()); this.isLogin = false;
                     }
         },
         (err) => { if (err != null && callback != null)
                    {
                        callback.SuccessCallback(err.ToString());
                    }
         });
 }
 public void logout(CometChatFormCallback callback)
 {
     cometchat.Logout(new CometChatCallback((JSONObject obj) =>
     {
         System.Console.Write("Logout success");
         this.isLogin = false;
         if (callback != null)
         {
             callback.SuccessCallback((string)obj);
         }
     }, (JSONObject obj) =>
     {
         System.Console.Write("Logout fail");
         if (callback != null)
         {
             callback.FailCallback((string)obj);
         }
     }));
 }