code: public void runOnUrlLoadPlugins(CrawlerContext context) {
  		LOGGER.debug("Running OnUrlLoadPlugins...");
  		counters.get(OnUrlLoadPlugin.class).inc();
  		for (Plugin plugin : plugins.get(OnUrlLoadPlugin.class)) {
  			if (plugin instanceof OnUrlLoadPlugin) {
  				try {
  					LOGGER.debug("Calling plugin {}", plugin);
  					((OnUrlLoadPlugin) plugin).onUrlLoad(context);
  				} catch (RuntimeException e) {
  					reportFailingPlugin(plugin, e);
  				}
  			}
  		}
  	}
docs: load and run the OnUrlLoadPlugins. The OnUrlLoadPlugins are run just after the Browser has
  gone to the initial url. Not only the first time but also every time the Core navigates back.
  Warning the instance of the browser offered is not a clone but the current and after wards
  used browser instance, changes and operations may cause 'strange' behaviour.
  <p>
  This method can be called from multiple threads with different {@link CrawlerContext}
  </p>
  
  @param context the current {@link CrawlerContext} for this crawler.