Is it possible to extend this plugin?

Is it possible to extend this plugin?

Hi , I´m using this plugin http://sharrre.com/ and trying to extend one of its functions


e.g.:  extend the String object
String.prototype.trim = function() {
     return this.toString().replace(/^\s+|\s+$/g, "");
};

But I can´t get it, I wonder if it will be possible..