if (lastSessions == null || !lastSessions.containsKey(session)) {
String instanceName = curSessions.get(session).getInstanceName();
SessionId sessionId = curSessions.get(session).getTypedSessionId();
try {
// add current-state listeners for new sessions
manager.addCurrentStateChangeListener(this, instanceName, sessionId.toString());
logger.info(manager.getInstanceName() + " added current-state listener for instance: "
+ instanceName + ", session: " + session + ", listener: " + this);
} catch (Exception e) {
logger.error("Fail to add current state listener for instance: " + instanceName
+ " with session: " + session, e);