#
            # class_label:              ->              class_label:
            #   names:                  ->                names:
            #     '0': negative              ->               - negative
            #     '1': positive              ->               - positive
            #
            if isinstance(feature.get("class_label"), dict) and isinstance(feature["class_label"].get("names"), dict):
                label_ids = sorted(feature["class_label"]["names"], key=int)
                if label_ids and [int(label_id) for label_id in label_ids] != list(range(int(label_ids[-1]) + 1)):
                    raise ValueError(
                        f"ClassLabel expected a value for all label ids [0:{int(label_ids[-1]) + 1}] but some ids are missing."
                    )
                feature["class_label"]["names"] = [feature["class_label"]["names"][label_id] for label_id in label_ids]
            return feature