Core data 在Swift 3中实现fetchedresultsviewcontroller

我试图在Swift 3中实现fetchedresultsviewcontroller，在将控制器的委托属性设置为self时遇到以下错误：

无法将“SomeRootViewController”类型的值分配给类型 “NSFetchedResultsControllerDelegate？”

SomeRootViewController.swift

@available(iOS 10.0, *)
@objc class SomeRootViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    var delegate: SomeRootViewControllerDelegate?
    public var context: NSManagedObjectContext!

    private let persistentContainer = NSPersistentContainer(name: "Accessory")


    fileprivate lazy var fetchedResultsController: NSFetchedResultsController<Accessory> = {
        // Create Fetch Request
        let fetchRequest: NSFetchRequest<Accessory> = Accessory.fetchRequest() as! NSFetchRequest<Accessory>

        // Configure Fetch Request
        fetchRequest.sortDescriptors = [NSSortDescriptor(key: "AccessoryAttributes.name", ascending: true)]

        // Create Fetched Results Controller
        let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.persistentContainer.viewContext, sectionNameKeyPath: nil, cacheName: nil)

        // Configure Fetched Results Controller
        fetchedResultsController.delegate = self //<<-- this is where error occurs

        return fetchedResultsController
    }()

@可用（iOS 10.0，*）
@objc类SomeRootViewController:UIViewController、UITableViewDataSource、UITableViewDelegate{
变量委托：SomeRootViewControllerDelegate？
公共变量上下文：NSManagedObjectContext！
private let persistentContainer=NSPersistentContainer（名称：“附件”）
fileprivate惰性变量fetchedResultsController:NSFetchedResultsController={
//创建提取请求
让fetchRequest:NSFetchRequest=附件。fetchRequest（）作为！NSFetchRequest
//配置提取请求
fetchRequest.sortDescriptors=[NSSortDescriptor（键：“AccessoryAttributes.name”，升序：true）]
//创建获取的结果控制器
让fetchedResultsController=NSFetchedResultsController（fetchRequest:fetchRequest，managedObjectContext:self.persistentContainer.viewContext，sectionNameKeyPath:nil，cacheName:nil）
//配置获取的结果控制器
fetchedResultsController.delegate=self/因为要将委托设置为self，所以还需要使SomeRootViewController符合NSFetchedResultsController委托协议，如下所示：

class SomeRootViewController: NSFetchedResultsControllerDelegate, UIViewController, UITableViewDataSource, UITableViewDelegate {

由于要将委托设置为self，因此还需要使SomeRootViewController符合NSFetchedResultsControllerDelegate协议，如下所示：

class SomeRootViewController: NSFetchedResultsControllerDelegate, UIViewController, UITableViewDataSource, UITableViewDelegate {