function sprintf() {
            var key = arguments[0], cache = sprintf.cache
            if (!(cache[key] && cache.hasOwnProperty(key))) {
                cache[key] = sprintf.parse(key)
            }
            return sprintf.format.call(null, cache[key], arguments)
        }
sprintf() for JavaScript 1.0.3
    https://github.com/alexei/sprintf.js