如何从NSFetchedResultsController获取唯一的对象？

// 创建NSFetchedResultsController对象
let fetchRequest: NSFetchRequest<NSManagedObject> = NSFetchRequest(entityName: "YourEntity")
fetchRequest.sortDescriptors = [NSSortDescriptor(key: "yourSortKey", ascending: true)]
let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: yourManagedObjectContext, sectionNameKeyPath: nil, cacheName: nil)

// 执行查询
do {
    try fetchedResultsController.performFetch()
} catch {
    print("Fetch error: \(error.localizedDescription)")
}

// 获取唯一的对象
if let objects = fetchedResultsController.fetchedObjects, let uniqueObject = objects.first {
    // 使用uniqueObject进行操作
    print(uniqueObject)
} else {
    print("No objects found")
}