Inheritance: IDisposable
        public void PeriodInvoker_By_PeriodTimeSpan(int milliSeconds) {
            var periodTimeSpan = TimeSpan.FromMilliseconds(milliSeconds);

            using(var periodInvoker = new PeriodInvoker(string.Empty, periodTimeSpan, PeriodAction, true)) {
                Thread.Sleep(1000);
            }
            Assert.IsTrue(_actionRaised);
        }
 [TestCase("0,30 * * * *")] // 매시, 매시 30분에 실행
 public void PeriodInvoker_By_PeriodFormat(string periodTimeFormat) {
     using(var periodInvoker = new PeriodInvoker(periodTimeFormat, PeriodAction, true)) {
         Thread.Sleep(TimeSpan.FromSeconds(3));
     }
     Assert.IsTrue(_actionRaised);
 }