/// <summary>
        /// 요청 응답을 string 으로 가져온다.
        /// </summary>
        /// <returns></returns>
        public string getString()
        {
            if (!isWorked)
            {
                doWork();
            }

            if (ContentType.ToLower().IndexOf("utf-8") >= 0 || CharacterSet.ToLower().IndexOf("utf-8") >= 0)
            {
                return(Encoding.UTF8.GetString(ResponseContent));
            }
            else
            {
                return(Encoding.Default.GetString(ResponseContent));
            }
        }