Chapter 8: Compile error "Use of undeclared type 'Message'"

Hello,
I’m trying to play with the exampled provided with the book in order to integrate the apn function in my project but, even the original example provided as final in the chapter 8 gave me this compile error at the following line in NotificationTableViewController.swift

" lazy private var fetchedResultsController: NSFetchedResultsController = { "
– Error : Use of undeclared type ‘Message’

Thank you very much for the help,
Alessandro Rossi

I just downloaded the project files, double-clicked on the xcode final project for chapter 8, changed the bundle identifier and then hit compile without issues.