#vulnerable code 
                                @Override
    public PdfObject getDestinationPage(final HashMap<Object, PdfObject> names) throws PdfException {
        PdfArray array = (PdfArray) names.get(getPdfObject());

        return array.get(0, false);
    } 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public PdfObject getDestinationPage(final HashMap<Object, PdfObject> names) throws PdfException {
        PdfArray array = (PdfArray) names.get(getPdfObject());

        return array != null ? array.get(0, false) : null;
    }