@Override
    public boolean isVirtual(MetaField metaField) {
        switch (metaField) {
            case KEY:
            case VALUE:
            case HEADERS:
            case HEADERS_TO_JSON_STR:
            case PARTITION:
            case OFFSET:
            case TIMESTAMP:
            case AUDIT_DATA_TIME:
                return true;
            default:
                return false;
        }
    }
true is upsert kafka connector
false is kafka connector
@return Boolean variable that decides connector option
inlong-sort/sort-common/src/main/java/org/apache/inlong/sort/protocol/node/extract/KafkaExtractNode.java