Actionscript 3 :: Why Is Casting Object (null) Not Null

When you cast null to an object using Object(null), the result is an object.When you cast undefined to an object using Object(undefined), the result is an object.But saying null as Object or undefined as Object remains null.Why is this? I can't find anything in the documentation about this.

The objects that result from these casts can have properties set on and read from them. It's as if the cast created information, or removed whatever special information the null and undefined values have. But there's no indication in the AS3 documentation that the null and undefined special types are actually objects.