/**
  * {@inheritdoc}
  */
 public function iterate(IterateEvent $event)
 {
     foreach ($this->doctrine->getManagers() as $name => $manager) {
         if (!$manager->isOpen()) {
             throw new \RuntimeException(sprintf('The doctrine manager: %s is closed', $name));
         }
         $manager->getUnitOfWork()->clear();
     }
 }