}

    /**
     * Adds a shutdown listener to be notified when the executor is shutting down.
     *
     * @param listener the shutdown listener to add
     */
    public void addShutdownListener(final ShutdownListener listener) {
        shutdownListener = listener;
    }

    /**
     * Interface for listening to shutdown events.
     */
    public interface ShutdownListener {
        /**

            sessionId = RandomStringUtils.randomAlphabetic(15);
        }
        resultBuf.append("Session Id: ").append(sessionId).append("\n");
        if (jobExecutor != null) {
            jobExecutor.addShutdownListener(() -> ComponentUtil.getProcessHelper().destroyProcess(sessionId));
        }

        final TimeoutTask timeoutTask = createTimeoutTask();
        try {
            executePython();

            sessionId = RandomStringUtils.randomAlphabetic(15);
        }
        resultBuf.append("Session Id: ").append(sessionId).append("\n");
        if (jobExecutor != null) {
            jobExecutor.addShutdownListener(() -> ComponentUtil.getProcessHelper().destroyProcess(sessionId));
        }

        final TimeoutTask timeoutTask = createTimeoutTask();
        try {
            executeSuggestCreator();

            sessionId = RandomStringUtils.randomAlphabetic(15);
        }
        resultBuf.append("Session Id: ").append(sessionId).append("\n");
        if (jobExecutor != null) {
            jobExecutor.addShutdownListener(() -> ComponentUtil.getProcessHelper().destroyProcess(sessionId));
        }

        final TimeoutTask timeoutTask = createTimeoutTask();
        try {
            executeThumbnailGenerator();

                resultBuf.append(' ').append(id);
            }
            resultBuf.append('\n');
        }

        if (jobExecutor != null) {
            jobExecutor.addShutdownListener(() -> ComponentUtil.getProcessHelper().destroyProcess(sessionId));
        }

        final TimeoutTask timeoutTask = createTimeoutTask();
        try {
            executeCrawler();