Doctrine\OXM\OXMException::mappingCacheNotConfigured PHP Method

    public static function mappingCacheNotConfigured()
    {
        return new self('Class Mapping Cache is not configured.');
    }

 /**
  * Ensures that this Configuration instance contains settings that are
  * suitable for a production environment.
  *
  * @throws OXMException If a configuration setting has a value that is not
  *                      suitable for a production environment.
  */
 public function ensureProductionSettings()
 {
     if (!$this->getMetadataCacheImpl()) {
         throw OXMException::mappingCacheNotConfigured();
     }
 }