code: private Extractors getExtractorsForMapName(String mapNameOrNull) {
          if (mapNameOrNull == null) {
              return Extractors.newBuilder(serializationService)
                      .build();
          }
          return mapServiceContext.getExtractors(mapNameOrNull);
      }
docs: Returns the value {@link Extractors} for the map with the given name. May be null in
  which case no extractors are returned.