Method offsetCommit

consumergroup.go:563–563

(offsetCommitRequestV2)

	heartbeat(heartbeatRequestV0) (heartbeatResponseV0, error)
	offsetFetch(offsetFetchRequestV1) (offsetFetchResponseV1, error)
	offsetCommit(offsetCommitRequestV2) (offsetCommitResponseV2, error)
	readPartitions(...string) ([]Partition, error)
}