* Sets the delay time in milliseconds when there are no URLs in the queue.
     *
     * @param delayMillisAtNoUrlInQueue the delay time in milliseconds when no URLs are available
     */
    public void setDelayMillisAtNoUrlInQueue(final long delayMillisAtNoUrlInQueue) {
        this.delayMillisAtNoUrlInQueue = delayMillisAtNoUrlInQueue;
    }

    /**
     * Gets the delay time in milliseconds before processing a URL.
     *