protected static PdfDictionary duplicatePdfDictionary(final PdfDictionary original, PdfDictionary copy, final PdfReader newReader) {
        if (copy == null)
            copy = new PdfDictionary();
        for (Object element : original.getKeys()) {
            PdfName key = (PdfName)element;
            copy.put(key, duplicatePdfObject(original.get(key), newReader));
        }
        return copy;
    }