}
private Resource executeWithJs(final VFS vfs, final Resource resource,
final Map<String, Object> options) throws IOException {
if (this.executor == null) {
this.executor = new JavaScriptExecutorFast("uglify-" + this.version, 9,
getClass());
this.executor.addScriptSource("module = {};", "rhino.js");
this.executor.addScriptFile(getClass().getResource(
"/uglify-" + this.version + "/uglify-js.js"));
this.executor.addCallScript("uglify(%s, {});");