How can I get the item being removed when CacheItemUpdateCallback is called

I want to avoid an item being removed from cache when expire in SOME OCASIONS

If i understand how CacheItemUpdateCallback works, i need to asign to expensiveObject the new object, in my case: the old one. But i cant access the item with HttpContext.Current.Cache[key],

my question: how to access the old item? or in other words, How prevent this item being removed in th开发者_高级运维e first place?

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You can use the HttpRuntime to access the Cache.