*
   * {@snippet :
   * for (B b0 : sets.get(0)) {
   *   for (B b1 : sets.get(1)) {
   *     ...
   *     ImmutableList<B> tuple = ImmutableList.of(b0, b1, ...);
   *     // operate on tuple
   *   }
   * }
   * }
   *
   * <p>Note that if any input set is empty, the Cartesian product will also be empty. If no sets at

    }

    String getCrawlerMetadataNameMapping();

    default Tuple3<String, String, String> getCrawlerMetadataNameMapping(final String name) {
        @SuppressWarnings("unchecked")
        Map<String, Tuple3<String, String, String>> params =
                (Map<String, Tuple3<String, String, String>>) propMap.get(CRAWLER_METADATA_NAME_MAPPING);
        if (params == null) {