No way of getting metadata, that was committed with OffsetAndMetadata

[tvoinarovskyi]

When we use consumer.commit({tp: OffsetAndMetadata(msg.offset+1, "Some metadata")}) the API requires us to pass the OffsetAndMetadata structure, but then that metadata can't be retured nowhere.
In Java Client it's returned as part of consumer.committed(tp) response. See https://kafka.apache.org/0101/javadoc/org/apache/kafka/clients/consumer/KafkaConsumer.html#committed(org.apache.kafka.common.TopicPartition)

@dpkp Any ideas how to go with API change to fix this? Like we can't just change the return value of committed at this point without a deprecation period.

[dpkp]

I think we can just add an optional parameter like consumer.committed(tp, metadata=True)