[Illustrator][JSX] double the stroke width of the selected item

strokeWidthTwice.jsx

(function () {
    if (app.documents.length > 0) {
        var selected = app.activeDocument.selection,
            i,
            magnification = 2;
        for (i = 0; i < selected.length; i++) {
            selected[i].strokeWidth *= magnification;
        }
    }
})();