public void resetBeginQuorumEpochTimer(long currentTimeMs) {
        beginQuorumEpochTimer.update(currentTimeMs);
        beginQuorumEpochTimer.reset(beginQuorumEpochTimeoutMs);
    }
In the context of LeaderState, an acknowledged voter means one who has acknowledged the current leader by either
responding to a `BeginQuorumEpoch` request from the leader or by beginning to send `Fetch` requests.
More specifically, the set of unacknowledged voters are targets for BeginQuorumEpoch requests from the leader until
they acknowledge the leader.
raft/src/main/java/org/apache/kafka/raft/LeaderState.java