src/Log/Processor/UniqueId.php
public function process(array $event)
    {
        $event = parent::process($event);

        $event['uniqueId'] = substr($event['extra']['requestId'], 0, 7);
        unset($event['extra']['requestId']);

        return $event;
    }
public function process(array $event)
    {
        $event = parent::process($event);

        $event['uniqueId'] = substr($event['extra']['requestId'], 0, 7);
        unset($event['extra']['requestId']);

        return $event;
    }
Processes a log message before it is given to the writers

@param  array $event

@return array