code: public void asXml(final StringBuilder sb) {
          sb.append("<Map>\n");
          for (int i = 0; i < data.size(); i++) {
              sb.append("  <Entry key=\"").append(data.getKeyAt(i)).append("\">").append((String)data.getValueAt(i))
                      .append("</Entry>\n");
          }
          sb.append("</Map>");
      }
docs: Formats this message as an XML fragment String into the given builder.
  
  @param sb format into this builder.