simple_cache.cs

    public class MemoryCache : IObjectCache
    {
        public T Get<T>(CacheKey key, DateTime absoluteExpiration, Func<T> load)
        {
            var policy = new System.Runtime.Caching.CacheItemPolicy();
            policy.AbsoluteExpiration = absoluteExpiration;

            return Get(key, policy, load);
        }

        public T Get<T>(CacheKey key, TimeSpan slidingExpiration, Func<T> load)
        {
            var policy = new System.Runtime.Caching.CacheItemPolicy();
            policy.SlidingExpiration = slidingExpiration;

            return Get(key, policy, load);
        }

        private T Get<T>(CacheKey key, System.Runtime.Caching.CacheItemPolicy policy, Func<T> load)
        {
            var keyStr = key.ToString();
            var cache = System.Runtime.Caching.MemoryCache.Default;
            T result = (T)cache[keyStr];

            if (result == null)
            {
                result = load();
                cache.Add(new System.Runtime.Caching.CacheItem(keyStr, result), policy);
            }

            return result;
        }
    }