code: protected static void destroyProcessGroup(String pgrpId,
                         long sleeptimeBeforeSigkill, boolean inBackground) {
      terminateProcessGroup(pgrpId);
      sigKill(pgrpId, true, sleeptimeBeforeSigkill, inBackground);
    }
docs: Destroy the process group.
  @param pgrpId Process group id of to-be-killed-processes
  @param sleeptimeBeforeSigkill The time to wait before sending SIGKILL
  after sending SIGTERM
  @param inBackground Process group is to be killed in the back ground with
  a separate thread