/// <summary>
        /// 收到 "本月已發送訊息數" 後會回覆的文字
        /// </summary>
        /// <returns></returns>
        private async Task <string> GetNumberOfMessagesSentThisMonthTips()
        {
            string result = "";
            NumberOfMessagesSentThisMonthResponseModel responseModel = new NumberOfMessagesSentThisMonthResponseModel();

            responseModel = await _lineClient.GetNumberOfMessagesSentThisMonthAsync();

            result = $"本月已發送訊息的數量為 : {responseModel.totalUsage}";

            return(result);
        }
        /// <summary>
        /// Gets the number of messages sent in the current month.
        /// The number of messages retrieved by this operation includes the number of messages sent from LINE Official Account Manager.
        /// The number of messages retrieved by this operation is approximate. To get the correct number of sent messages, use LINE Official Account Manager or execute API operations for getting the number of sent messages.
        /// Note: LINE@ accounts cannot call this API endpoint.
        /// </summary>
        /// <returns>NumberOfMessagesSentThisMonthResponseModel</returns>
        public async Task <NumberOfMessagesSentThisMonthResponseModel> GetNumberOfMessagesSentThisMonthAsync()
        {
            NumberOfMessagesSentThisMonthResponseModel responseModel = new NumberOfMessagesSentThisMonthResponseModel();
            string para      = "/quota/consumption";
            string apiResult = null;

            apiResult = await Utility.DoLineHttpGetAsync(MessagingApiUrl.MessageUrl, para, accessToken);

            responseModel = JsonConvert.DeserializeObject <NumberOfMessagesSentThisMonthResponseModel>(apiResult);

            return(responseModel);
        }