*/
    public boolean isForceStop() {
        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.
     *