braddunbar/backbone — comment on commit 2f654d2676ef6e44150ba4a10b90be53567d9e8d
File: backbone.js line 170
By braddunbar:

I thought I might need to add a comment for that. The first one is to ensure that `_changed` exists during `set`. The second one is to remove any changes caused by `set`. We could check for it's existence in `set` but it seems unnecessary when we can just do it once here.