boolean isInAP(PdfDictionary dic, PdfName check) {
        PdfDictionary appDic = dic.getAsDict(PdfName.AP);
        if (appDic == null)
            return false;
        PdfDictionary NDic = appDic.getAsDict(PdfName.N);
        return NDic != null && NDic.get(check) != null;
    }