option) && $this->option !== '') { $this->key = $this->option; } } public function convert(LoggerLoggingEvent $event) { if (isset($this->key)) { return $event->getMDC($this->key); } else { $buff = array(); $map = $event->getMDCMap(); foreach($map as $key => $value) { $buff []= "$key=$value"; } return implode(', ', $buff); } } }