void sentHeartbeat(long now) {
        lastHeartbeatSend = now;
        heartbeatInFlight = true;
        update(now);
        heartbeatTimer.reset(rebalanceConfig.heartbeatIntervalMs);

        if (log.isTraceEnabled()) {
            log.trace("Sending heartbeat request with {}ms remaining on timer", heartbeatTimer.remainingMs());
        }
    }
A helper class for managing the heartbeat to the coordinator
clients/src/main/java/org/apache/kafka/clients/consumer/internals/Heartbeat.java