Value of type 'AppDelegate' has no member 'persistentContainer'

[mdrame]

static let context: NSManagedObjectContext = {

        guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { fatalError() }
        
   
        let persistentContainer = appDelegate.persistentContainer /* error = Value of type 'AppDelegate' has no member 'persistentContainer' */
        
        let context = persistentContainer.viewContext
        
        return context
   
    }()