title: Prevent accessing CoreData object access after deletion
body: <p>So here's the problem I am facing. I have a UITableView backed by NSFetchedResultsController. Now at application startup I update the data source which involves making multiple network calls and processing the incoming data. If the user deletes one of the rows while the data source is being updated, accessing the deleted data in the asynchronous network callback crashes the app. How do I handle this scenario gracefully?  </p>