protected void miss( HostedConnection source ) {
        log.log(Level.WARNING, "Session data is null for:{0} on connection:{1}", new Object[]{attributeName, source});
    }
Called internally when there is no session object
 for the current attribute name attached to the passed source
 HostConnection.  Default implementation logs a warning.
jme3-networking/src/main/java/com/jme3/network/util/SessionDataDelegator.java