* Add tests for batch update completion handler calling
* Ensure we call all completion handlers after collection view updates
* Tweak it
* Fix the doc
* Minor improvements
* Document addCompletionHandler better
* Add unit test to confirm that supplementary items must be contained within actual sections
* [ASLayoutInspecting] Deprecate collectionView:numberOfSectionsForSupplementaryNodeOfKind:
* Add another test to dig deeper into UICollectionView