a2-11.swift

func flushData() {
        
    let fetchRequest:NSFetchRequest<NSFetchRequestResult> = NSFetchRequest<NSFetchRequestResult>(entityName: "ToDoItem")
    let objs = try! mockPersistantContainer.viewContext.fetch(fetchRequest)
    for case let obj as NSManagedObject in objs {
        mockPersistantContainer.viewContext.delete(obj)
    }
    try! mockPersistantContainer.viewContext.save()

}