extendString = function () {
        var _add = function (name, body) { return Object.defineProperty(String.prototype, name, _noEnum(body)); };
        _add('fromBase64', function () { return decode(this); });
        _add('toBase64', function (urlsafe) { return encode(this, urlsafe); });
        _add('toBase64URI', function () { return encode(this, true); });
        _add('toBase64URL', function () { return encode(this, true); });
        _add('toUint8Array', function () { return toUint8Array(this); });
    }
extend String.prototype with relevant methods