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

   var body: some View {
      NavigationStack {
         List(appData.filteredItems) { book in
            CellBook(book: book)
         }.navigationTitle(Text("Books"))
         .toolbar {
            ToolbarItem(placement: .topBarTrailing) {
               NavigationLink(destination: SettingsView(), label: {
                  Image(systemName: "gearshape")
               })
            }
         }
      }
   }
}