@Override
    public void applyReadableMetadata(List<String> metadataKeys, DataType producedDataType) {
        this.metadataKeys = metadataKeys;
        this.producedDataType = producedDataType;
    }
Metadata that is appended at the end of a physical source row.
inlong-sort/sort-flink/sort-flink-v1.15/sort-connectors/postgres-cdc/src/main/java/org/apache/inlong/sort/postgre/PostgreSQLTableSource.java