@Override
        public void run() {
            if (log.isLoggable(Level.FINE)) {
                log.log(Level.FINE, "Visitor session " + sessionName + ": Received message " + message);
            }
            try {
                if (message instanceof VisitorInfoMessage) {
                    handleVisitorInfoMessage((VisitorInfoMessage)message); // always replies
                } else {
                    handleDocumentMessage((DocumentMessage)message); // always replies on error
                }
            } catch (Throwable t) {
                com.yahoo.protect.Process.logAndDie("Caught unhandled error when processing message", t);
            }
        }
Called from the constructor to ensure control and data handlers
are set and initialized.
documentapi/src/main/java/com/yahoo/documentapi/messagebus/MessageBusVisitorSession.java