public Item GetById(int id)
        {
            IList <Item> items;

            if (CacheWrapper.Exists(cacheKey))
            {
                CacheWrapper.Get(cacheKey, out items);
            }
            else
            {
                items = _items;
            }

            return(items.FirstOrDefault(i => i.Id.Equals(id)));
        }
        public IList <Item> GetAll()
        {
            IList <Item> retVal;

            if (CacheWrapper.Exists(cacheKey))
            {
                CacheWrapper.Get(cacheKey, out retVal);
            }
            else
            {
                retVal = _items;
                CacheWrapper.Add(retVal, cacheKey, DateTimeOffset.UtcNow.AddMinutes(1));
            }

            return(retVal);
        }