docs: public void validate() throws Exception {
          if (crawlStorageFolder == null) {
              throw new Exception("Crawl storage folder is not set in the CrawlConfig.");
          }
          if (politenessDelay < 0) {
              throw new Exception("Invalid value for politeness delay: " + politenessDelay);
          }
          if (maxDepthOfCrawling < -1) {
              throw new Exception(
                  "Maximum crawl depth should be either a positive number or -1 for unlimited depth" +
                  ".");
          }
          if (maxDepthOfCrawling > Short.MAX_VALUE) {
              throw new Exception("Maximum value for crawl depth is " + Short.MAX_VALUE);
          }
      }