@Override
 public List<SignatureVo> getAllSignatures(UserVo userVo, DocumentVo documentVo) {
   Account actor = accountService.findByLsUuid(userVo.getLsUuid());
   try {
     DocumentEntry document = documentEntryService.findById(actor, documentVo.getIdentifier());
     return signatureTransformer.disassembleList(
         new ArrayList<Signature>(document.getDocument().getSignatures()));
   } catch (BusinessException e) {
     logger.error("Can't find document : " + documentVo.getIdentifier() + ": " + e.getMessage());
   }
   return null;
 }
  @Override
  public SignatureVo getSignature(UserVo currentSigner, DocumentVo documentVo) {
    Account actor = accountService.findByLsUuid(currentSigner.getLsUuid());
    try {
      DocumentEntry document = documentEntryService.findById(actor, documentVo.getIdentifier());
      SignatureVo res = null;
      for (Signature signature : document.getDocument().getSignatures()) {
        if (signature.getSigner().equals(actor)) {
          res = signatureTransformer.disassemble(signature);
          break;
        }
      }
      return res;

    } catch (BusinessException e) {
      logger.error("Can't find document : " + documentVo.getIdentifier() + ": " + e.getMessage());
    }
    return null;
  }