code: @Override
      public synchronized Renderable<?> render(Controller controller, Map<String, Object> variables) {
          HashMap<String, Object> map = new HashMap<>(variables);
          if (!map.containsKey(ExtendedOGNLExpressionEvaluator.BUNDLE_VAR_KEY)) {
              map.put(ExtendedOGNLExpressionEvaluator.BUNDLE_VAR_KEY, bundle);
          }
          return templateEngine.process(this, controller, router, assets, map);
      }
docs: Renders the template.
  
  @param controller the controller having requested the rendering.
  @param variables  the parameters
  @return the rendered object.