public function onFlush(OnFlushEventArgs $eventArgs)
    {
        //reduce the amount of flushes to increase performances !
        //you can also activate the log from the claroline.persistence.object_manager service when you use it
        //if you want additional informations about transactions
        if ($this->activateLog) {
            $this->log('onFlush event fired !!!', LogLevel::DEBUG);

            if (self::DEBUG_NONE !== $this->debugLevel) {
                $stack = debug_backtrace();

                foreach ($stack as $call) {
                    if (isset($call['file'])) {
                        $file = $call['file'];
                        if (self::DEBUG_CLAROLINE === $this->debugLevel) {
                            if (strpos($file, 'claroline')) {
                                $this->logTrace($call);
                            }
                        } elseif (self::DEBUG_ALL === $this->debugLevel) {
                            $this->logTrace($call);
                        } elseif (self::DEBUG_VENDOR === $this->debugLevel) {
                            if (strpos($file, $this->debugVendor)) {
                                $this->logTrace($call);
                            }
                        }
                    }
                }

                $this->log('Data printed !');
            }
        }
    }