if (queueSession == null) {
queueSession = WebSocketNegotiationHandler.establishNegotiation(val, this, erraiService);
if (queueSession != null) {
LOGGER.trace("Negotiation done for errai session: {} on websocket session: {}", queueSession.getSessionId(),
session.getId());
queueSession.addSessionEndListener(new SessionEndListener() {
@Override
public void onSessionEnd(SessionEndEvent event) {
if (session.isOpen()) {
LOGGER.warn("Errai queue session closed: {}", queueSession.getSessionId());
}