}

    /**
     * Forces all crawlers to stop immediately.
     * Sets the force stop flag and stops all active crawler instances.
     */
    private void forceStop() {
        systemHelper.setForceStop(true);
        if (crawlerList != null) {
            for (final Crawler crawler : crawlerList) {
                crawler.stop();
            }
        }
    }

    /**

        return forceStop.get();
    }

    /**
     * Sets the force-stop state of the system.
     *
     * @param b true to force-stop the system.
     */
    public void setForceStop(final boolean b) {
        forceStop.set(b);
    }

    /**
     * Generates a document ID.
     *
     * @param map A map of data for the document.
     * @return A unique document ID.
     */