// endElement(): merges contents of fGlobalIDConstraintMap with the
// top of fGlobalMapStack into fGlobalIDConstraintMap.
public void endElement() {
if (fGlobalMapStack.isEmpty()) return; // must be an invalid doc!
Hashtable oldMap = (Hashtable)fGlobalMapStack.pop();
Enumeration keys = oldMap.keys();
while(keys.hasMoreElements()) {
IdentityConstraint id = (IdentityConstraint)keys.nextElement();
ValueStoreBase oldVal = (ValueStoreBase)oldMap.get(id);
if(oldVal != null) {
ValueStoreBase currVal = (ValueStoreBase)fGlobalIDConstraintMap.get(id);