/**
  * @param string $entity
  *
  * @return ClassMetadataCollection
  */
 private function getMetadataForClass($entity)
 {
     foreach ($this->registry->getManagers() as $em) {
         $cmf = new DisconnectedClassMetadataFactory();
         $cmf->setEntityManager($em);
         if (!$cmf->isTransient($entity)) {
             return new ClassMetadataCollection(array($cmf->getMetadataFor($entity)));
         }
     }
     return new ClassMetadataCollection(array());
 }