copy URL reference

copy URL

 if let fileRefURL = (url as NSURL).fileReferenceURL() as NSURL? {
            print(fileRefURL)
            let pasteboard = NSPasteboard.general
            pasteboard.clearContents()
            pasteboard.writeObjects([fileRefURL])
            pasteboard.setString(fileRefURL.relativeString, forType: .fileURL)
        }