     
     // MARK: -
     
-    internal func _createUIDifNecessary(){
+    private func _createUIDifNecessary(){
         if _id==Default.NO_UID{
             _id=Bartleby.createUID()
             Registry.register(self) // register on creation

    
    // The id is always  created locally
    // and used as primary index by MONGODB
    internal var _id:String=Default.NO_UID
    
    private var _referenceName:String=Default.NO_NAME
    

        super.init()
        _id=String(decoder.decodeObjectOfClass( NSString.self, forKey:Default.UID_KEY)! as NSString? )
        referenceName=String(decoder.decodeObjectOfClass( NSString.self, forKey:Default.REFERENCE_NAME_KEY)! as NSString?)
        Registry.register(self)//registration on deserialization
    }
    
    public class func supportsSecureCoding() -> Bool{
