private function locateDescription($entityClass)
    {
        $entityName     = preg_replace('~^.*?(\w+)$~', '\1', $entityClass);
        $definitionFile = $entityName . '.xml';
        $filename       = $this->locator->findFile($definitionFile);

        if (!is_null($filename)) {
            return $filename;
        }

        throw new EntityNotDefinedException($entityClass);
    }