* @throws IOException
     */
    public void addComments(FdfReader fdf) throws IOException{
        if (readers2intrefs.containsKey(fdf))
            return;
        PdfDictionary catalog = fdf.getCatalog();
        catalog = catalog.getAsDict(PdfName.FDF);
        if (catalog == null)
            return;
        PdfArray annots = catalog.getAsArray(PdfName.ANNOTS);
        if (annots == null || annots.size() == 0)
            return;
        registerReader(fdf, false);
        IntHashtable hits = new IntHashtable();
        HashMap<String, PdfObject> irt = new HashMap<String, PdfObject>();
        ArrayList<PdfObject> an = new ArrayList<PdfObject>();
        for (int k = 0; k < annots.size(); ++k) {
            PdfObject obj = annots.getPdfObject(k);
            PdfDictionary annot = (PdfDictionary)PdfReader.getPdfObject(obj);
            PdfNumber page = annot.getAsNumber(PdfName.PAGE);
            if (page == null || page.intValue() >= reader.getNumberOfPages())
                continue;
            findAllObjects(fdf, obj, hits);
            an.add(obj);
            if (obj.type() == PdfObject.INDIRECT) {
                PdfObject nm = PdfReader.getPdfObject(annot.get(PdfName.NM));
                if (nm != null && nm.type() == PdfObject.STRING)
                    irt.put(nm.toString(), obj);
            }
        }
        int arhits[] = hits.getKeys();
        for (int k = 0; k < arhits.length; ++k) {
            int n = arhits[k];
            PdfObject obj = fdf.getPdfObject(n);
            if (obj.type() == PdfObject.DICTIONARY) {
                PdfObject str = PdfReader.getPdfObject(((PdfDictionary)obj).get(PdfName.IRT));
                if (str != null && str.type() == PdfObject.STRING) {
                   PdfObject i = irt.get(str.toString());
                   if (i != null) {
                       PdfDictionary dic2 = new PdfDictionary();
                       dic2.merge((PdfDictionary)obj);
                       dic2.put(PdfName.IRT, i);
                       obj = dic2;
                   }
                }
            }
            addToBody(obj, getNewObjectNumber(fdf, n, 0));
        }
        for (int k = 0; k < an.size(); ++k) {
            PdfObject obj = an.get(k);
            PdfDictionary annot = (PdfDictionary)PdfReader.getPdfObject(obj);
            PdfNumber page = annot.getAsNumber(PdfName.PAGE);
            PdfDictionary dic = reader.getPageN(page.intValue() + 1);
            PdfArray annotsp = (PdfArray)PdfReader.getPdfObject(dic.get(PdfName.ANNOTS), dic);
            if (annotsp == null) {
                annotsp = new PdfArray();
                dic.put(PdfName.ANNOTS, annotsp);
                markUsed(dic);
            }
            markUsed(annotsp);
            annotsp.add(obj);
        }
    }