NelmioApiDocBundle/DependencyInjection/NelmioApiDocExtension.php

<?php

namespace Nelmio\ApiDocBundle\DependencyInjection;

use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\Config\Definition\Processor;
use Symfony\Component\Config\FileLocator;

class NelmioApiDocExtension extends Extension
{
    /**
     * {@inheritdoc}
     */
    public function load(array $configs, ContainerBuilder $container)
    {
        $processor = new Processor();
        $configuration = new Configuration();
        $config = $processor->processConfiguration($configuration, $configs);

        $container->setParameter('nelmio_api_doc.api_name', $config['name']);

        $loader = new XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
        $loader->load('formatters.xml');
        $loader->load('request_listener.xml');
        $loader->load('services.xml');
    }
}