@SuppressWarnings("unchecked")
    private <T> T readMetadata(RowData consumedRow, KafkaDynamicSink.WritableMetadata metadata) {
        final int pos = metadataPositions[metadata.ordinal()];
        if (pos < 0) {
            return null;
        }
        return (T) metadata.converter.read(consumedRow, pos);
    }
Serialize for list it is used for multiple sink scenes when a record contains mulitple real records.

@param consumedRow The consumeRow
@param timestamp The timestamp
@return List of ProducerRecord
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/kafka/src/main/java/org/apache/inlong/sort/kafka/DynamicKafkaSerializationSchema.java