public void handleMessage( RpcResponseMessage msg ) {
        if( log.isLoggable(Level.FINEST) ) {
            log.log(Level.FINEST, "handleMessage({0})", msg);
        }    
        ResponseHolder holder = responses.remove(msg.getMessageId());
        if( holder == null ) {
            return;
        }
        holder.setResponse(msg);       
    }
Called internally when an RpcResponseMessage is received from 
 the remote connection.
jme3-networking/src/main/java/com/jme3/network/service/rpc/RpcConnection.java