docs: private void startAppendTimer() {
      // Set a timer that will be used to periodically synchronize with other nodes
      // in the cluster. This timer acts as a heartbeat to ensure this node remains
      // the leader.
      log.trace("Starting append timer");
      appendTimer = raft.getThreadContext().schedule(Duration.ZERO, raft.getHeartbeatInterval(), this::appendMembers);
    }