Marks the specified items as invalid so that their layout information can be updated.
- macOS 10.11+
A set of
NSIndexobjects. Each index path represents an item whose layout needs to be recomputed.
Call this method when you want the layout object to recompute attributes for a specific set of items. The items you provide are added to the
invalidated property. You can call this method more than once to create a merged set of items.