*/
    int state = 0;

    String name = "Transport" + id++;
    Thread thread;
    TransportException te;

    protected HashMap response_map = new HashMap( 4 );

    protected abstract void makeKey( Request request ) throws IOException;
    protected abstract Request peekKey() throws IOException;
    protected abstract void doSend( Request request ) throws IOException;

    }


    /**
     * @return the number of known usages
     */
    protected long getUsageCount () {
        return this.usageCount.get();
    }


    protected abstract long makeKey ( Request request ) throws IOException;


    protected abstract Long peekKey () throws IOException;


    protected abstract void doSend ( Request request ) throws IOException;