public function convert($source)
    {
        $xpath = new \DOMXPath($source);

        $defaultConfig = $this->getDefaultConfiguration($xpath);
        $configuration = ['default' => $defaultConfig];

        foreach ($this->getAllLanguages($xpath) as $language) {
            $configuration[$language] = $this->getLanguageConfiguration($xpath, $language, $defaultConfig);
        }

        return $configuration;
    }