ClassCastException in SimpleBookmark.getBookmark()

[ghost]

I sometimes get the following exception in the latest version of OpenPDF when getting bookmarks from a PDF:

Caused by: java.lang.ClassCastException: com.lowagie.text.pdf.PdfString cannot be cast to com.lowagie.text.pdf.PdfDictionary
at com.lowagie.text.pdf.SimpleBookmark.getBookmark(SimpleBookmark.java:289)
.....

The ClassCastException occurs here:
https://github.com/rtfarte/OpenPDF/blob/master/openpdf/src/main/java/com/lowagie/text/pdf/SimpleBookmark.java#L289