code: protected void gatherForwardRenderData(HtmlResponse response) {
          final RenderData data = newRenderData();
          response.getRegistrationList().forEach(reg -> reg.register(data));
          validateHtmlBeanIfNeeds(response); // manage validator
          data.getDataMap().forEach((key, value) -> runtime.registerData(key, value)); // so validated here
      }
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