code: private boolean isBookmarkable()
     {
        Boolean result = bookmarkable.get();
        if (result == null)
        {
           result = false;
           bookmarkable.set(result);
        }
        return result;
     }
docs: <b>NOTE:</b> This method should only be used by the getBookmarkableURL and getActionURL methods, for the purposes
  of rewriting form URLs (which do not include viewParameters.)
  
  @return Bookmarkable state - defaults to false if not previously set;