docs: public static StringConsumers buildConsumer(Properties props, final String topic,//
                                                  final String groupId,//
                                                  final IMessageListener<String> listener,//
                                                  final int threads
      ) {
          if (props == null || props.isEmpty()) {
              props = new Properties();
          }
          props.put("groupid", groupId);
          return new StringConsumers(props, topic, threads, listener);
      }