src/main/java/js/net/EventStreamManagerImpl.java
@Remote
	@Public
	public String subscribe(EventStreamConfig config) {
		SessionID sessionID = new SessionID();
		log.debug("Store event stream parameters for session |%s|.", sessionID);
		sessions.put(sessionID, config);
		return sessionID.getValue();
	}
@Remote
	@Public
	public String subscribe(EventStreamConfig config) {
		SessionID sessionID = new SessionID();
		log.debug("Store event stream parameters for session |%s|.", sessionID);
		sessions.put(sessionID, config);
		return sessionID.getValue();
	}
Subscribes to events stream and returns session ID. This method is remote accessible and public. It returns a session ID
with a short life time, for about 10 seconds.
<p>
This method creates a new {@link SessionID} and stores given configuration object to {@link #sessions} map, with created
session ID as key. Session storage is ephemere. It lasts only for {@link #SUBSCRIBE_TTL} period of time; after that
session ID becomes stale.
<p>
This method should be followed by {@link #createEventStream(String)}, with returned session ID as argument.

@param config events stream configuration object.
@return events stream session ID.