DOM L3 LS - DocumentLS::unload

Would it be possible to add "unload" as a method on the interface "DocumentLS" in DOM Level 3 Load and Save?  The return value could either be a boolean, returning true if a document was already loaded and false if not, or it could just be void.

I believe the impact would be minimal to implementers, and this symmetry would be useful in many circumstances.  The symantics of "load" shouldn't have to change at all (such as the behavior of a load call on a Document that has already completed another successful load call).

Thanks,
-Daniel