         if (corner.count != 4){
             assertionFailure({ () -> String in
                 "Wrong argument, must be 4 but \(corner.count) input"
-            }())
+                }())
         }
         let img = UIImage(named: self)!
         return img.resizableImageWithCapInsets(UIEdgeInsetsMake(CGFloat(corner[0]), CGFloat(corner[1]), CGFloat(corner[2]), CGFloat(corner[3])))

    /// json dictionary wrapped by Accessor
    public var adJsonObject:ADAccessor{
        get{
            return self.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)!.adToJsonObject()
        }
    }


extension NSData{

    /// get json dictionary wrapped by accessor object
    public var adJsonObject:ADAccessor{
        get{
            return ADAccessor(NSJSONSerialization.JSONObjectWithData(self, options: NSJSONReadingOptions.AllowFragments, error: nil)!)
        }
    }

    /// to utf8 string
    public var adUtf8String:String{
        get{
            return "\(NSString(data: self, encoding: NSUTF8StringEncoding))"
        }
    }

    /// to url safe base64 string
