How can I determine if a PDF destination (bookmark) is named or explicit?

Q: I know that I can set a named bookmark with the following:

String key = "namedbookmark";
Action action = Action.CreateGoto(key,
Destination.CreateFit(doc.PageFind(19).Current()) );

What I need to know is how to find out if a bookmark is a named or
explicit bookmark.
A: When you get the destination object from the bookmark Action,
PDFNet will automatically search for the named destination so users
typically don't need to distinguish between named or explicit

Action action = bookmark_item.GetAction();
if (action.IsValid()) {
  if (action.GetType() == Action.Type.e_GoTo) {
    Destination dest = action.GetDest();
    if (dest.IsValid()) {
      Page page = dest.GetPage();
      ... page.GetIndex()...

In case you still need to figure out if the destination is named or
explicit you can check the type of the underlying SDF/Cos object. For

if (dest.IsString()) {
  // PDF 1.2 Named Destination
else if (dest.IsName()) {
  // PDF 1.1 Named Destination
else if (dest.IsArray()) {
  // Explicit destination