public String invoke(String requestId, PartnerLink partnerLink, Operation operation, Element outgoingMessage)
throws UninitializedPartnerEPR {
// TODO: think we should move the dao creation into bpelprocess --mbs
MessageExchangeDAO mexDao = _dao.getConnection().createMessageExchange(new GUID().toString(),
MessageExchangeDAO.DIR_BPEL_INVOKES_PARTNERROLE);
mexDao.setStatus(MessageExchange.Status.REQ);
mexDao.setOperation(operation.getName());
mexDao.setPortType(partnerLink.getModel().getPartnerRolePortType().getQName());
mexDao.setPartnerLinkModelId(partnerLink.getModel().getId());