class SignatureUtil {

    public boolean signatureCoversWholeDocument(String name) {
        getSignatureNames();
        if (!sigNames.containsKey(name))
            return false;
        try {
            ContentsChecker signatureReader = new ContentsChecker(document.getReader().getSafeFile().createSourceView());
            return signatureReader.checkWhetherSignatureCoversWholeDocument(acroForm.getField(name));
        } catch (IOException e) {
            throw new PdfException(e);
        }
    }

    public  SignatureUtil(PdfDocument document);

}