private void writeParameters(ObjectOutputStream dout, Object[] params)
        throws IOException
    {
        int n = params.length;
        dout.writeInt(n);
        for (int i = 0; i < n; ++i)
            if (params[i] instanceof Proxy) {
                Proxy p = (Proxy)params[i];
                dout.writeObject(new RemoteRef(p._getObjectId()));
            }
            else
                dout.writeObject(params[i]);
    }