*/
    @Override
    public ResponseData execute(final RequestData request) {
        return switch (request.getMethod()) {
        case GET -> doGet(request.getUrl());
        case HEAD -> doHead(request.getUrl());
        case POST -> doPost(request.getUrl());
        default -> throw new CrawlerSystemException(request.getMethod() + " method is not supported.");
        };
    }

    /**

    }

    /**
     * Executes a HEAD request for the given URL.
     * @param url The URL to request.
     * @return The ResponseData.
     */
    @Override
    public ResponseData doHead(final String url) {
        try {
            final ResponseData responseData = processRequest(url, false);
            responseData.setMethod(Constants.HEAD_METHOD);
            return responseData;

        this.charset = charset;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.robot.client.S2RobotClient#doHead(java.lang.String)
     */
    @Override
    public ResponseData doHead(final String url) {
        try {
            final ResponseData responseData = processRequest(url, false);
            responseData.setMethod(Constants.HEAD_METHOD);

        }
        return doHttpMethod(url, httpGet);
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.http.HttpClient#doHead(java.lang.String)
     */
    @Override
    public ResponseData doHead(final String url) {
        HttpUriRequest httpHead;
        try {
            httpHead = new HttpHead(url);
        } catch (final IllegalArgumentException e) {

        }
        return doHttpMethod(url, httpGet);
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.http.HttpClient#doHead(java.lang.String)
     */
    @Override
    public ResponseData doHead(final String url) {
        ClassicHttpRequest httpHead;
        try {
            httpHead = new HttpHead(url);
        } catch (final IllegalArgumentException e) {

                            return -1;
                        }
                        int toRead = Math.min(buffer.length, remaining);
                        System.arraycopy(includeContent, index[0], buffer, 0, toRead);
                        index[0] += toRead;
                        return toRead;
                    });

				currentPartBytes := v - partOffset
				currentPartDareBytes := v - partDarePkgOffset
				if currentPartBytes < toRead {
					toRead -= currentPartBytes
					l += getEncSize(currentPartDareBytes)
				} else {
					// current part has the last
					// byte required
					lbPartOffset := partOffset + toRead - 1

					// round up the lbPartOffset
					// to the end of the
					// corresponding DARE package

     * @throws IOException if an I/O error occurs
     */
    protected <T extends Response> long doSend(final Request request, final T response, final Set<RequestParam> params, final long timeout)
            throws IOException {
        final long firstKey = prepareRequests(request, response, params, timeout);
        doSend(request);
        return firstKey;
    }

    /**
     * @param request
     * @param response

    /**
     * Sends a request to the remote endpoint.
     *
     * @param request the request to send
     * @throws IOException if an I/O error occurs
     */
    protected abstract void doSend(Request request) throws IOException;

    /**
     * Receives a response from the remote endpoint.
     *
     * @param response the response object to populate
     * @throws IOException if an I/O error occurs

   *
   * @return the source of this event.
   */
  public Object getSource() {
    return source;
  }

  /**
   * Returns the wrapped, 'dead' event, which the system was unable to deliver to any registered
   * subscriber.
   *
   * @return the 'dead' event that could not be delivered.
   */
  public Object getEvent() {
    return event;
  }

  @Override
  public String toString() {