sectionSnapshotHandlers
The diffable data source’s handlers for expanding and collapsing items.
Declaration
@NSCopying var sectionSnapshotHandlers: __UICollectionViewDiffableDataSourceSectionSnapshotHandlers { get set }Discussion
Provide section snapshot handlers to support the expanding or collapsing of items in your collection view.
Use the snapshotForExpandingParentItemHandler handler to customize the snapshot that returns when a particular parent item is expanded.