public LocalClientSession getClientSession(String connectionManagerDomain, StreamID streamID) {
        Map<StreamID, LocalClientSession> sessions = sessionsByManager.get(connectionManagerDomain);
        if (sessions != null) {
            return sessions.get(streamID);
        }
        return null;
    }
Returns the ClientSession with the specified stream ID that is being hosted by the
specified connection manager.

@param connectionManagerDomain the connection manager that is handling the connection
       of the session.
@param streamID the stream ID created by the connection manager for the session.
@return the ClientSession with the specified stream ID.
xmppserver/src/main/java/org/jivesoftware/openfire/multiplex/ConnectionMultiplexerManager.java