protected function addPrismJSInAssetic(ContainerBuilder $container, array $config)
    {
        if ($config['js'] !== false && $config['css'] !== false) {
            $container->prependExtensionConfig('assetic', array(
                'assets' => array(
                    'prismjs_js' => $config['js'],
                    'prismjs_css' => $config['css'],
                ),
            ));
        } elseif ($config['js'] === false && $config['css'] !== false) {
            throw new InvalidConfigurationException('You have enabled PrismJS supports but js parameter is missing.');
        } elseif ($config['js'] !== false && $config['css'] === false) {
            throw new InvalidConfigurationException('You have enabled PrismJS supports but css parameter is missing.');
        }
    }