Is UndoManager necessary in the CoreDataBooks sample?

I have been working开发者_JS百科 on a first application for some time based on the CoreDataBooks sample. I notice that if I delete all of the UndoManager code, the sample still seems to function normally. I do not care about the shake event, so is this something I can safely delete in a basic table-oriented application (similar to Contacts)? I have spent time with the documentation and on the web, and I do not see how I would use this functionality. Am I missing something basic?

NSManagedObjectContext on ADC is pretty clear on this topic

You can set the undo manager to nil to disable undo support. This provides a performance benefit if you do not want to support undo for a particular context, for example in a large import process—see Core Data Programming Guide.

If you don't need undo support disable it by setting undoManager nil in your context (or do not set it at all)