@Override
    public void onMemberEpochUpdated(Optional<Integer> memberEpoch, Optional<String> memberId) {
        if (!memberEpoch.isPresent() && memberInfo.memberEpoch.isPresent()) {
            log.info("Member {} won't include member id and epoch in following offset " +
                "commit/fetch requests because it has left the group.", memberInfo.memberId.orElse("unknown"));
        }
        memberInfo.memberId = memberId;
        memberInfo.memberEpoch = memberEpoch;
    }
Update latest member ID and epoch used by the member.

@param memberEpoch New member epoch received. To be included in the new request.
@param memberId Current member ID. To be included in the new request.
clients/src/main/java/org/apache/kafka/clients/consumer/internals/CommitRequestManager.java