private function parseFileToDOM($file)
    {
        try {
            $dom = XmlUtils::loadFile($file, array($this, 'validateSchema'));
        } catch (\InvalidArgumentException $e) {
            throw new InvalidArgumentException(sprintf('Unable to parse file "%s".', $file), $e->getCode(), $e);
        }

        $this->validateExtensions($dom, $file);

        return $dom;
    }