code: @Programmatic
      public String render(
              final String templateName,
              final String templateChars,
              final Object dataModel) throws IOException, TemplateException {
          return templateLoader
                  .withTemplateSource(templateName, templateChars, new TemplateLoaderFromThreadLocal.Block() {
              @Override
              public String exec(final TemplateSource templateSource) throws IOException, TemplateException {
                  final StringWriter sw = new StringWriter();
                  final Template template = cfg.getTemplate(templateSource.getTemplateName());
                  template.process(dataModel, sw);
                  return sw.toString();
              }
          });
      }
docs: Uses the provided document type (reference) and atPath to lookup the template's text.
  
  @param dataModel - will usually be a strongly-typed DTO, but a {@link Map} can also be used.