Tree-like parameters from services into flat

AppExtension.php

<?php
namespace Vendor\AppBundle\DependencyInjection;

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

class VendorAppExtension extends Extension
{

    final public function load(array $configs, ContainerBuilder $container)
    {
        $this->loadInternal($this->processConfiguration($this->getConfiguration($configs, $container), $configs), $container);
    }

    protected function loadInternal(array $mergedConfig, ContainerBuilder $container)
    {
        $loader = new Loader\YamlFileLoader($container, new FileLocator(__DIR__ . '/../Resources/config'));
        $loader->load('services.yml');
        $this->flatifyParameter($container, $this->getAlias());
    }

    private function flatifyParameter(ContainerBuilder $container, $globalKey, $value = null)
    {
        if (is_null($value)) {
            $value = $container->getParameter($globalKey);
        }
        if (is_array($value)) {
            foreach ($value as $key => $value) {
                $this->flatifyParameter($container, $globalKey . '.' . $key, $value);
            }
        } else {
            $container->setParameter($globalKey, $value);
        }
    }
}