       static var attributeDescription: NSAttributeDescription {
         let attributeDescription = NSAttributeDescription()
         attributeDescription.name = name
-        attributeDescription.attributeType = .StringAttributeType
-        attributeDescription.optional = false
+        attributeDescription.attributeType = .stringAttributeType
+        attributeDescription.isOptional = false
         return attributeDescription
       }
     }

     - parameter name: Name of the CloudKit custom zone.
     */
    func saveZoneName(name: String) {
      let preference = NSEntityDescription.insertNewObjectForEntityForName(Entity.name, inManagedObjectContext: context) as! Preference
      preference.key = Default.zoneName
      preference.value = name
      try! context.save()

     - parameter name: Name of the CloudKit custom zone subscription.
     */
    func saveZoneSubscriptionName(name: String) {
      let preference = NSEntityDescription.insertNewObject(forEntityName: Entity.name, into: context) as! Preference
      preference.key = Default.zoneSubscriptionName
      preference.value = name
      try! context.save()
