code: @Override
      protected String format(String request) {
          String result = null;
          ByteArrayOutputStream bos = new ByteArrayOutputStream();
          try {
              ByteArrayInputStream bis = new ByteArrayInputStream(request.getBytes());
              Document doc = new SAXBuilder().build(bis);
              bis.close();
              Format format = Format.getCompactFormat();
              // To not have the ? in the declaration interpreted as regular expressions.
              format.setOmitDeclaration(true);
              XMLOutputter out = new XMLOutputter(format);
              out.output(doc, bos);
              result = new String(bos.toByteArray());
              bos.close();
          } catch (Exception e) {
              log.error(null, e);
          }
          return result;
      }
docs: {@inheritDoc}