/** {@inheritDoc} */
  public void serializeTo(Element element) throws DocumentSerializationException {
    for (Iterator i = transportMetrics.iterator(); i.hasNext(); ) {
      TransportMetric transportMetric = (TransportMetric) i.next();

      DocumentSerializableUtilities.addDocumentSerializable(
          element, "transportMetric", transportMetric);
    }
    if (moduleClassID != null) {
      DocumentSerializableUtilities.addString(element, "moduleClassID", moduleClassID.toString());
    }
  }