Patch Set 2:

> What are you going to do about the TODO markers for actual > diff output? Just allow the caller to supply you 
> the OutputStream and pass that to the DiffFormatter?

To be honest I haven't though about it yet, but a way to provide an OutputStream is one option. Another could be returning value objects for each diff (similar to DiffEntry). I was going to open a separate bugzilla/change set for that as soon this one is merged.