code: public static String get(final String templateName, final Map<String, Object> data) {
          StringWriter writer = new StringWriter();
          write(templateName, data, writer);
          return writer.toString();
      }
docs: Process with given template + data and get result as a string.
  
  @param templateName
  filename of the .ftl file
  @param data
  data to fill in the template, as pairs of key-values
  @return processed result from template and data