docs: private static Class<ElasticsearchClient> findClass(int version) throws ClassNotFoundException {
          String className = "fr.pilato.elasticsearch.crawler.fs.client.v" + version + ".ElasticsearchClientV" + version;
          logger.trace("Trying to find a class named [{}]", className);
          Class<?> aClass = Class.forName(className);
          boolean isImplementingInterface = ElasticsearchClient.class.isAssignableFrom(aClass);
          if (!isImplementingInterface) {
              throw new IllegalArgumentException("Class " + className + " does not implement " + ElasticsearchClient.class.getName() + " interface");
          }
  
          return (Class<ElasticsearchClient>) aClass;
      }