public String diff_prettyHtmlUsingCss(LinkedList<Diff> diffs,
                                        String insertClass,
                                        String deleteClass,
                                        String equalClass) {
        StringBuilder html = new StringBuilder();
    int i = 0;
    for (Diff aDiff : diffs) {
      String text = aDiff.text.replace("&", "&amp;").replace("<", "&lt;")
          .replace(">", "&gt;").replace("\n", "&para;<br>")
          .replace("'", "&#39;").replace("\"", "&quot;"); // djk: added ' and "

      switch (aDiff.operation) {
      case INSERT:
          html.append("<ins class=\"").append(insertClass).append("\">").append(text)
              .append("</ins>");
        break;
      case DELETE:
          html.append("<del class=\"").append(deleteClass).append("\">").append(text)
              .append("</del>");
        break;
      case EQUAL:
          html.append("<span class=\"").append(equalClass).append("\">").append(text)
              .append("</span>");
        break;
      }
      if (aDiff.operation != Operation.DELETE) {
        i += aDiff.text.length();
      }
    }
    return html.toString();
  }