code: public void callService(String url, String templateName, Object model, XmlHttpResponse result, Map<String, Object> headers) {
          doHttpPost(url, templateName, model, result, headers, XmlHttpResponse.CONTENT_TYPE_XML_TEXT_UTF8);
          setContext(result);
      }
docs: Performs POST to supplied url of result of applying template with model.
  All namespaces registered in this environment will be registered with result.
  @param url url to post to.
  @param templateName name of template to use.
  @param model model for template.
  @param result result to populate with response.
  @param headers headers to add.