@Override
    public DynamicTableSource copy() {
        MongoDBTableSource source =
                new MongoDBTableSource(
                        physicalSchema,
                        hosts,
                        username,
                        password,
                        database,
                        collection,
                        connectionOptions,
                        copyExisting,
                        copyExistingQueueSize,
                        batchSize,
                        pollMaxBatchSize,
                        pollAwaitTimeMillis,
                        heartbeatIntervalMillis,
                        localTimeZone,
                        enableParallelRead,
                        splitMetaGroupSize,
                        splitSizeMB,
                        metricOption);
        source.metadataKeys = metadataKeys;
        source.producedDataType = producedDataType;
        return source;
    }
Metadata that is appended at the end of a physical source row.
inlong-sort/sort-flink/sort-flink-v1.15/sort-connectors/mongodb-cdc/src/main/java/org/apache/inlong/sort/mongodb/MongoDBTableSource.java