private CachedObjectInfo AddCacheInfo(object key)
        {
            if (key == null)
            {
                return(null);
            }
            if (IsContainCacheInfo(key))
            {
                return(GetCacheInfo(key));
            }
            CachedObjectInfo item = new CachedObjectInfo();

            item.InitCache(key, mReleaser);
            pool.Add(item);
            return(item);
        }