Notify when @FetchRequest changes?

Hello

@FetchRequest(
        entity: Book(),
        sortDescriptors: []
    ) var books: FetchedResults<Book>

How can I get notified when books changes?

I was thinking about putting this...

 .onReceive(NotificationCenter.default.publisher(for: .NSManagedObjectContextDidSave), perform: { _ in})

... in my main View but this would notify me if anything gets saved and that is not what I want. I want to get notified just if a certain FetchRequest changes (in this case books)?

And in another thread I was told to use...

.onRecevie(books.publisher){ _ in
      ....
}

...however using this code publishes each member of the sequence as a separate element, I want it to publish just once?

Thank You!