private Engine getEngine() {
   if (engine == null) {
     engine = Engine.createCompilingEngine();
     engine.registerNamedRenderer(new HtmlEscapeRenderer());
     engine.registerNamedRenderer(new LogRenderer(this));
     engine.registerNamedRenderer(new IndexRenderer());
     engine.registerNamedRenderer(new RelativePathRenderer(this));
     engine.registerNamedRenderer(new NumberRenderer());
     engine.registerNamedRenderer(new TimeRenderer());
     engine.registerNamedRenderer(new StringRenderer());
     engine.registerRenderer(Result.class, new ResultRenderer());
     engine.registerRenderer(Node.class, new NodeRenderer(engine, getTemplate("index-node.html")));
     engine.registerAnnotationProcessor(new AnnoCommandResults());
   }
   return engine;
 }