protected function verifySeedDirectory($path)
    {
        if (!is_dir($path)) {
            throw new \InvalidArgumentException(sprintf(
                'Seed directory "%s" does not exist',
                $path
            ));
        }

        if (!is_writable($path)) {
            throw new \InvalidArgumentException(sprintf(
                'Seed directory "%s" is not writable',
                $path
            ));
        }
    }