private HeartbeatRequestMessage<ID> constructHeartbeatRequestMessage(
      final ID mbr) {
    final int reqId = requestId.getAndIncrement();
    final HeartbeatRequestMessage<ID> hrm = new HeartbeatRequestMessage<>(mbr, reqId);
    hrm.setRecipient(mbr);

    return hrm;
  }
Record member activity at a specified time
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/fd/GMSHealthMonitor.java