@sielay Excellent, would you mind writing a quite test suite for this? Would love to add this to 0.10.7 if possible! Apologies for the delay getting back to you!

I fixed the conflicts and merged this in 2ac1fb9. I don't think it needs unit tests, it's just adding a callback argument. Thanks a bajillion @sielay — you've made working on #45 much easier! 😄

@Aendrew thanks, forgot about this one already ;)