public bool UpdateAccount(TaiKhoan tk)
        {
            RestRequest request = new RestRequest("account", Method.PUT);
            string data = Post(request, tk);
            bool result = (bool)DeserializeObject(data, typeof(bool));

            return result;
        }
        //protected string access_token = ConfigurationManager.AppSettings["access_token"];
        public int CreateAccount(TaiKhoan account)
        {
            RestRequest request = new RestRequest("account", Method.POST);
            string data = Post(request, account);
            int result = (int)DeserializeObject(data, typeof(int));

            return result;
        }