code: public function decodeSubject($subject)
      {
          if ($this->hasQueue() && $queue = $this->getQueue()) {
              return $queue->getMessageParameters('subject');
          }
  
          return base64_decode(substr($subject, strlen('=?utf-8?B?'), -1 * strlen('?=')));
      }
docs: Returns raw subject
  
  @param $subject
  @return string