struct ContentView: View {
   @Environment(ApplicationData.self) private var appData

   var body: some View {
      NavigationStack {
         List(appData.userData) { book in
            CellBook(book: book)
         }
         .navigationTitle(Text("Books"))
         .toolbarTitleDisplayMode(.inlineLarge)
         .toolbar {
            ToolbarItemGroup(placement: .primaryAction) {
               Button("Add Book", systemImage: "plus.app", action: {
                  print("Adding Book...")
               })
            }
            ToolbarItemGroup(placement: .secondaryAction) {
               Button("Save", systemImage: "folder", action: {
                  print("Saving...")
               })
            }
         }
      }
   }
}