// is a depth-first traversal.
Stack schemasToProcess = new Stack();
schemasToProcess.push(fRoot);
while (!schemasToProcess.empty()) {
XSDocumentInfo currSchemaDoc =
(XSDocumentInfo)schemasToProcess.pop();
Element currDoc = currSchemaDoc.fSchemaElement;
if(DOMUtil.isHidden(currDoc, fHiddenNodes)){
// must have processed this already!