public function prepend(ContainerBuilder $container)
{
if ($container->hasExtension('nelmio_cors')) {
$file = __DIR__ . '/../Resources/config/nelmio_cors.yml';
$config = Yaml::parse(file_get_contents($file));
$container->prependExtensionConfig('nelmio_cors', $config);
$container->addResource(new FileResource($file));
}
}