docs: private FieldExtractor _createExtractorFor(Metadata metadata) {
          // Boot metadata tags that are not supported in this version of Elasticsearch
          if (version.onOrAfter(EsMajorVersion.V_6_X)) {
              // 6.0 Removed support for TTL and Timestamp metadata on index and update requests.
              switch (metadata) {
                  case TTL: // Fall through
                  case TIMESTAMP:
                      return new UnsupportedMetadataFieldExtractor(metadata, version);
              }
          }
  
          return createExtractorFor(metadata);
      }