public NameClass union(XSWildcard.Union wc) {
NameClass nc = null;
for (Iterator itr = wc.iterateNamespaces(); itr.hasNext();) {
String ns = (String) itr.next();
if(nc==null) nc = new NsNameClass(ns);
else
nc = new ChoiceNameClass(nc,new NsNameClass(ns));
}
// there should be at least one.
assert nc!=null;