docs: protected synchronized void submitTask(SpiderTask task) {
  		if (isStopped()) {
  			log.debug("Submitting task skipped (" + task + ") as the Spider process is stopped.");
  			return;
  		}
  		if (isTerminated()) {
  			log.debug("Submitting task skipped (" + task + ") as the Spider process is terminated.");
  			return;
  		}
  		this.tasksTotalCount++;
  		try {
  			this.threadPool.execute(task);
  		} catch (RejectedExecutionException e) {
  			if (log.isDebugEnabled()) {
  				log.debug("Submitted task was rejected (" + task + "), spider state: [stopped=" + isStopped() + ", terminated="
  						+ isTerminated() + "].");
  			}
  		}
  	}