- iOS 3.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
Performs the undo operations in the last undo group (whether top-level or nested), recording the operations on the redo stack as a single group.
Performs the operations in the last group on the redo stack, if there are any, recording them on the undo stack as a single group.