code: public void runOnRevisitStatePlugins(CrawlerContext context,
  			StateVertex currentState) {
  		LOGGER.debug("Running OnRevisitStatePlugins...");
  		counters.get(OnRevisitStatePlugin.class).inc();
  		for (Plugin plugin : plugins.get(OnRevisitStatePlugin.class)) {
  			if (plugin instanceof OnRevisitStatePlugin) {
  				LOGGER.debug("Calling plugin {}", plugin);
  				try {
  					((OnRevisitStatePlugin) plugin).onRevisitState(context,
  							currentState);
  				} catch (RuntimeException e) {
  					reportFailingPlugin(plugin, e);
  				}
  			}
  		}
  	}
docs: load and run the onRevisitStateValidator. As a difference to other SessionPlugins this plugin
  needs an explicit current state because the session.getCurrentState() does not contain the
  correct current state because we are in back-tracking
  
  @param context      the current {@link CrawlerContext} for this crawler.
  @param currentState the state the 'back tracking' operation is currently in