docs: public synchronized void restart() {
  
          restartManagementWatchdogs();
          // shutdown all watchdogs
          Set copy = new HashSet(registeredWachdogs.values());
          Iterator iter = copy.iterator();
          while (iter.hasNext()) {
              Watchdog wd = (Watchdog) iter.next();
              if (wd.isUseless()) {
                  wd.kill();
                  this.deregisterWatchdog(wd);
                  if (log.isInfoEnabled()) {
                      log.info("WatchdogRegistry.restart() : Watchdog " + wd.getId() + " closed");
                  }
              } else if (!wd.isAlive() && !wd.isKilled()) {
                  wd.restart();
                  if (log.isInfoEnabled()) {
                      log.info("WatchdogRegistry.restart() : Watchdog " + wd.getId() + " restarted");
                  }
              }
          }
  
      }