//Original Java code for European Example. 
//Please view in a non-proportional font such as Lucida Console. 

public class Message{ 
    public string source;
    public String destination;
    public String contents;
}
public class Station{ 
    public String stationID;
    public String type;
    public Message inBuffer, outBuffer;
    public void accept(){ 
        outBuffer = inBuffer;
        send();
    }
    public void send(){ 
        GetNext().inBuffer = this.outBuffer;
        GetNext.accept();
    }
    public void print(String s){ 
        System.out.println(s);
    }
    protected Station GetNext(){...} 
    protected PrintServer GetPrinter(){...}
}
public class NetworkTester extends Station{ 
    public void testNetwork(){ 
        Message m = new Message();
        m.source = stationID;
        m.destination = stationID;
        m.contents = "NTNT";
        outBuffer = m;
        send();
    }
    public void accept(){ 
        if(inBuffer.source == this)
            print(inBuffer.contents);
        else super.accept();
    }
}
public class PrintServer extends Station{ 
    public void accept(){ 
        if(inBuffer.destination == this)
            print(inBuffer.contents);
        else super.accept();
    }
}
public class WorkStation extends Station{ 
    public void originate(){ 
        Message m = new Message();
        m.source = stationID;
        m.destination = GetPrinter().stationID;
        m.contents = "NTNT";
        outBuffer = m;
        send();
    }
    public void accept(){ 
        if(inBuffer.source == this)print("ERR");
        else super.accept();
    }
}