Doctrine\ODM\CouchDB\Mapping\ClassMetadataFactory::__construct PHP Method

    public function __construct(DocumentManager $dm)
    {
        $this->dm = $dm;
        $config = $this->dm->getConfiguration();
        $this->setCacheDriver($config->getMetadataCacheImpl());
        $this->driver = $config->getMetadataDriverImpl();
        if (!$this->driver) {
            throw new \RuntimeException('No metadata driver was configured.');
        }
    }