code: public boolean crawlTopics() {
          if (prop.get(PROPERTY_LINK_CRAWLER) == null) {
              return true;
          }
          return prop.get(PROPERTY_LINK_CRAWLER).toString().equals(ANT_INVOKER_EXT_PARAM_CRAWL_VALUE_TOPIC);
      }
docs: Retrieve the link crawling behaviour.
  @return {@code true} if crawl links in topics, {@code false} if only crawl links in maps