OffsetCommitCb

Set offset commit callback for use with consumer groups

The results of automatic or manual offset commits will be scheduled for this callback and is served by consume() or commitSync()

If no partitions had valid offsets to commit this callback will be called with \p err == NO_OFFSET which is not to be considered an error.

The \p offsets list contains per-partition information: - \c topic The topic committed - \c partition The partition committed - \c offset: Committed offset (attempted) - \c err: Commit error