code: public void clean() {
  	log.debug("[clean] Cleaning world");
  
  	for (Robot bot : robotsPosition.keySet()) {
  	    bot.die("World cleanup");
  	    if (robotsPosition.containsKey(bot)) {
  		log.warn("[clean] Robot did not unregister itself. Removing it");
  		remove(bot);
  	    }
  	}
  
      }
docs: Called to dispose of the world