protected function cleanHistory()
    {
        $createdAt = new \DateTime();
        $logs = $this->instance->getLogs();
        foreach($logs as $log) {
            if(($createdAt->getTimestamp() - $log->getCreatedAt()->getTimestamp()) > $this->expiredTimestamp) {
                $this->instance->removeLog($log);
            }
        }
    }