/// <summary>
        /// 定周期処理
        /// </summary>
        public async Task Start()
        {
            string prevId = "";
            //スケジューラーをキャンセルするToken(?)
            var token = CancellationToken.None;

            using (Felica felica = new Felica()) {
                while (!token.IsCancellationRequested)
                {
                    //引数1 : 遅延処理
                    //引数2 : 非同期したい処理の内容
                    await Task.WhenAll(Task.Delay(50), Task.Run(async() => {
                        string studentId = felica.GetStudentID();
                        if (!prevId.Equals(studentId))
                        {
                            if (studentId == "")
                            {
                                StudentID = "";
                                Time      = "";
                            }
                            else
                            {
                                StudentID         = studentId;
                                DateTime dateTime = DateTime.Now;
                                Time = dateTime.ToString("HH時mm分ss秒");
                                await FirebaseManager.Instance.PushDataBase(studentId, dateTime);
                                Console.WriteLine(StudentID + " : " + dateTime.ToString("yyyy-MM-dd HH:mm:ss"));
                            }
                        }
                        prevId = studentId;
                    }, token));
                }
            }
        }