@SuppressWarnings({"HardCodedStringLiteral"})
  public static void writeExternal(
      final Element element,
      final Map<String, SmartRefElementPointer> persistentEntryPoints,
      final JDOMExternalizableStringList additional_annotations) {
    Element entryPointsElement = new Element("entry_points");
    entryPointsElement.setAttribute(VERSION_ATTR, VERSION);
    for (SmartRefElementPointer entryPoint : persistentEntryPoints.values()) {
      assert entryPoint.isPersistent();
      entryPoint.writeExternal(entryPointsElement);
    }

    element.addContent(entryPointsElement);
    if (!additional_annotations.isEmpty()) {
      try {
        additional_annotations.writeExternal(element);
      } catch (WriteExternalException ignored) {
      }
    }
  }