             guard let object = storage.object(forKey: key as NSString) else {
                 return nil
             }
-            if object.expired {
+            if object.isExpired {
                 return nil
             }
             object.extendExpiration(extendingExpiration)

            }
        }
        
        var expired: Bool {
            return estimatedExpiration.isPast
        }
    }

                    keys.remove(key)
                    continue
                }
                if object.isExpired {
                    storage.removeObject(forKey: nsKey)
                    keys.remove(key)
                }
