CoreData堆栈与框架内的持久性容器

Question

我尝试构建一个内部带有CoreData的框架。我用来自iOS 10文件的容器初始化CoreData堆栈是这样的

class CoreDataStack {

lazy var persistentContainer: NSPersistentContainer = {
    let container = NSPersistentContainer(name: "MySDK")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    return container
}()

// MARK: - Core Data Saving support

func saveContext() {
    let context = persistentContainer.viewContext
    if context.hasChanges {
        do {
            try context.save()
        } catch {
            let nserror = error as NSError
            fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
        }
    }
}

func insert(check: Check) {
    guard let entityDescription = NSEntityDescription.entity(forEntityName: "CheckEntity", in: persistentContainer.viewContext) else { return }

    let managedObject = CheckEntity(entity: entityDescription, insertInto: persistentContainer.viewContext)

    managedObject.total = Int64(check.total)


    if let payment = check.payment {
        guard let paymentEntity = NSEntityDescription.entity(forEntityName: "PaymentEntity", in: persistentContainer.viewContext) else { return }
        let paymentEntityObject = PaymentEntity(entity: paymentEntity, insertInto: persistentContainer.viewContext)

        paymentEntityObject.amount = Int64(payment.amount)
        managedObject.addToPayment(paymentEntityObject)
    }

    for item in check.items {
        guard let entityDescription = NSEntityDescription.entity(forEntityName: "CheckItemEntity", in: persistentContainer.viewContext) else { return }
        let printerCheckItemEntity = CheckItemEntity(entity: entityDescription, insertInto: persistentContainer.viewContext)


        printerCheckItemEntity.uuid = item.uuid
        managedObject.addToItems(printerCheckItemEntity)
    }

    saveContext()
}

}

问题是，当我尝试调用方法insert时会崩溃

  

2019-01-14 18：30：04.115533 + 0300 MySDKTest [20465：33363837] ***   由于未捕获的异常而终止应用程序   'NSInvalidArgumentException'，原因：'+ entityForName：nil不是   合法的NSManagedObjectContext参数搜索实体名称   'CheckEntity'

我在做什么错了？