docs: @SuppressWarnings("unchecked")
    private static List<Map<String, ?>> checkObjectList(List<?> rawList) {
      for (int i = 0; i < rawList.size(); i++) {
        if (!(rawList.get(i) instanceof Map)) {
          throw new ClassCastException(
              String.format("value %s for idx %d in %s is not object", rawList.get(i), i, rawList));
        }
      }
      return (List<Map<String, ?>>) rawList;
    }