public void Can_Add_And_Expire_Struct_Strongly_Typed_With_Null()
        {
            var now = DateTime.Now;

            AppPolicyCache.Insert("DateTimeTest", () => now, new TimeSpan(0, 0, 0, 0, 200));
            Assert.AreEqual(now, AppCache.GetCacheItem <DateTime>("DateTimeTest"));
            Assert.AreEqual(now, AppCache.GetCacheItem <DateTime?>("DateTimeTest"));

            Thread.Sleep(300); // sleep longer than the cache expiration

            Assert.AreEqual(default(DateTime), AppCache.GetCacheItem <DateTime>("DateTimeTest"));
            Assert.AreEqual(null, AppCache.GetCacheItem <DateTime?>("DateTimeTest"));
        }