* @exception IOException If there is a problem writing the MoML.
*/
public void exportMoML(Writer out, String prefix) throws IOException {
XmlElement element = new XmlElement(_type, _attributes);
element.setPCData(_label);
element.writeXML(out, prefix);
}
/** Return the value of the attribute with the given name.
* Throw an exception if there is no attribute with the
* given name in this schematic.