         return false
     }
 
-    public func upsert(instances: [Collectible])->Bool {
+    public func upsert(instances: [Collectible]) -> Bool {
         var result=true
         for instance in instances {
             result=result&&self.upsert(instance)


    // MARK: delete

    public func delete(instance: Collectible)->Bool {
        if let collection=self._collectionByName(instance.d_collectionName) as? CollectibleCollection {
            return collection.removeObject(instance)
        }


     - returns: the instance
     */
    public static func registredObjectByUID<T: Collectible>(UID: String) -> T? {
        return _objectByUID[UID] as? T
    }

