code: public String getHtml(Formatter formatter, String value) {
          String result = null;
          if (value != null) {
              if ("".equals(value)) {
                  result = "";
              } else {
                  String formattedResponse = formatter.format(value);
                  result = "<pre>" + StringEscapeUtils.escapeHtml4(formattedResponse) + "</pre>";
              }
          }
          return result;
      }
docs: Formats supplied value for display as pre-formatted text in FitNesse page.
  @param formatter formatter to use to generate pre-formatted text.
  @param value value to format.
  @return HTML formatted version of value.