public function identifyClass(Rid $rid)
    {
        $map = $this->getMap();
        $splitRid = explode(':', ltrim($rid->getValue(), '#'));
        $clusterId = $splitRid[0];

        foreach ($map as $class => $clusters) {
            if (in_array($clusterId, $clusters)) {
                return $class;
            }
        }

        throw MappingException::noClusterForRid($rid);
    }