code: public function save($action, $type)
      {
          $id = $this->getId($action, $type);
          $fileName = $this->dir . static::DATA_DIR . $id;
          $file = serialize($this->limits[$id]);
  
          // Write the updated records
          if (isset($this->tFiles[$id]) && $this->tFiles[$id]->isOpened()) {
              $writer = new \PicoAuth\Storage\File\FileWriter(
                  $fileName,
                  ["handle"=>$this->tFiles[$id]->getHandle()]
              );
              $writer->write($file);
          } else {
              throw new \RuntimeException("Transaction file not opened.");
          }
      }
docs: {@inheritdoc}
  
  Save must be part of an exclusive transaction.