FileReference supports files larger than 4 gb... what's the point?

Recently reading FileReference manual 开发者_如何转开发on Adobe LiveDocs, I stumbled upon an interesting note in the description for the size property, that I've never noticed before:

Note: In the initial version of ActionScript 3.0, the size property was defined as a uint object, which supported files with sizes up to about 4 GB. It is now implemented as a Number object to support larger files.

...larger files? Larger then 4 GB?..

What's the point having support for such big files, if Flash still doesn't let to work with them without loading them into memory first? Or this has been changed? Or it's about AIR only?

It's unlikely that this is about FlashPlayer's capabilities in any way. I think it simply was a general design flaw in the FileReference class. That class is supposed to model all possible file references. If the file system allows for files larger than 4gb and such can't be represented correctly by a FileReference instance this model does not do what it's supposed to - be able to represent all possible file references. The initial version just represented all file references to files below 4 gb in size. Someone noticed that flaw in the initial design and fixed it.