public void TestFiveSecondTimeoutStruct()
{
var key = "time2";
var now = DateTime.Now;
_cache.Add(key, CacheExtensions.Wrap(now, DateTime.UtcNow.Add(new TimeSpan(0, 0, 5))));
Thread.Sleep(new TimeSpan(0, 0, 2));
var cached = CacheExtensions.Unwrap(_cache.Get <DateTime>(key));
Assert.Equal(now, cached);
Thread.Sleep(new TimeSpan(0, 0, 5));
Assert.Null(_cache.Get <string>(key));
}