Trick, how to add a generic function available for each NSManagedObject subclass

Extension for all NSManagedObject Subclass

    extension NSObjectProtocol where Self: NSManagedObject {
        
        static func findAllWithPredicate(searchTerm: NSPredicate?, inContext context: NSManagedObjectContext = NSManagedObjectContext.MR_defaultContext()) -> [Self] {
        
            //You can implement the fetchrequest here by yourself, but now I'm using MagicalRecord service to keep it simple
            return self.MR_findAllWithPredicate(searchTerm, inContext: context) as! [Self]
        }
    }

Usage (There is no cast required here, but the result is a [AnswerObject]):

    let unsynchedObjects = AnswerObject.findAllWithPredicate(NSPredicate(format: "synchronized == false"))