// elements
final EnumSet<Element> encountered = EnumSet.noneOf(Element.class);
while (reader.hasNext() && reader.nextTag() != END_ELEMENT) {
final Element element = Element.forName(reader.getLocalName());
if (!encountered.add(element)) {
throw ParseUtils.unexpectedElement(reader);
}
if (element.equals(Element.SERVLET)) {
parseServletElement(reader, subsystem);
} else {
throw ParseUtils.unexpectedElement(reader);
}
}