private StringData convertToString(JsonNode jsonNode) {
        if (jsonNode.isContainerNode()) {
            return StringData.fromString(jsonNode.toString());
        } else {
            return StringData.fromString(jsonNode.asText());
        }
    }
Creates a runtime converter which assuming input object is not null.
inlong-sort/sort-flink/base/src/main/java/org/apache/inlong/sort/base/format/JsonToRowDataConverters.java