public void Get_ReturnsNullWhenItemInvalidated()
        {
            CachingService cachingService = new CachingService();

            cachingService.Put("abc", "response", TimeSpan.FromSeconds(0));
            string response = cachingService.Get("abc") as string;

            Assert.Null(response);
        }
        public void Put_ResponseCached()
        {
            CachingService cachingService = new CachingService();

            cachingService.Put("abc", "response", TimeSpan.FromSeconds(10));
            string response = cachingService.Get("abc") as string;

            Assert.Equal("response", response);
        }
        public void Put_NullResponseNotCached()
        {
            CachingService cachingService = new CachingService();

            cachingService.Put("abc", null, TimeSpan.FromSeconds(10));
            string response = cachingService.Get("abc") as string;

            Assert.Null(response);
        }