/**
     * Skips an unexpected or unrecognized message.
     *
     * @throws IOException if an I/O error occurs
     */
    protected abstract void doSkip() throws IOException;

    /**
     * Sends a request and waits for the corresponding response.
     *
     * @param request the request to send
     * @param response the response object to populate

    /**
     * Skip a response with the given key
     *
     * @param key the key of the response to skip
     * @throws IOException if an I/O error occurs
     */
    protected abstract void doSkip(Long key) throws IOException;

    /**
     * Checks if the transport is disconnected.
     *
     * @return whether the transport is disconnected
     */
    public boolean isDisconnected() {

                if (LogStream.level >= 6) {
                    Hexdump.hexdump(log, BUF, 4, size);
                }
            }
        }
    }

    @Override
    protected void doSkip() throws IOException {
        final int size = Encdec.dec_uint16be(sbuf, 2) & 0xFFFF;
        if (size < 33 || 4 + size > rcv_buf_size) {
            /* log message? */
            in.skip(in.available());