void writeStatistics(Element element) {
    element.setAttribute(ATTRIBUTE_COUNT, String.valueOf(getUsageCount()));
    element.setAttribute(ATTRIBUTE_LAST_SHOWN, String.valueOf(getLastTimeShown()));
    element.setAttribute(ATTRIBUTE_LAST_USED, String.valueOf(getLastTimeUsed()));
    element.setAttribute(ATTRIBUTE_SHOWN_COUNT, String.valueOf(getShownCount()));
  }
void writeStatistics(Element element)