private void initiateSuspicion(ID mbr, String reason) {
    if (services.getJoinLeave().isMemberLeaving(mbr)) {
      return;
    }
    sendSuspectRequest(Collections.singletonList(new SuspectRequest<>(mbr, reason)));
  }
Record member activity at a specified time
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/fd/GMSHealthMonitor.java