@Override
        public ClientRegistrationMessage readObject( ByteBuffer data, Class c ) throws IOException {
    
            // Read the null/non-null marker
            if (data.get() == 0x0)
                return null;
 
            ClientRegistrationMessage msg = new ClientRegistrationMessage();
            
            msg.gameName = StringSerializer.readString(data);
            msg.id = data.getLong();
            msg.version = data.getInt();
            
            return msg;
        }
A message-specific serializer to avoid compatibility issues
 between versions.  This serializer is registered to the specific
 SERIALIZER_ID which is compatible with previous versions of the 
 SM serializer registrations... and now will be forever.
jme3-networking/src/main/java/com/jme3/network/message/ClientRegistrationMessage.java