Emberjs sort hasMany association as a computed property

I have two models, folder and files. A folder has many files. If I say folder.get('files') I get all the files associated with that folder ordered by id. I would like the array of files to be order by something other then the id; lets say createDate. If possible, I do not want to make a computed property that has a different name then files.

Any help would greatly be appreciated?