                 
             case "NSData":
                 let data = attributeValue as NSData
-                return data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.Encoding64CharacterLineLength)
+                return data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.allZeros)
                 
             default:
                 return nil

                let transformer = NSValueTransformer(forName: NSKeyedUnarchiveFromDataTransformerName)!
                
                // unarchive
                return transformer.transformedValue(jsonValue)
            }
            
            // custom transformer
            let transformer = NSValueTransformer(forName: valueTransformerName!)!
            
            // convert to original type
            return transformer.reverseTransformedValue(jsonValue)
        }
        
        return nil

                let data = transformer!.reverseTransformedValue(attributeValue) as NSData
                
                // convert to string (for JSON export)
                return data.base64EncodedStringWithOptions(NSDataBase64EncodingOptions.allZeros)
            }
            
            // custom transformer
