Symfony\Component\DependencyInjection\ContainerBuilder::hasExtension PHP Method

    public function hasExtension($name)
    {
        return isset($this->extensions[$name]) || isset($this->extensionsByNs[$name]);
    }

 /**
  * Allow an extension to prepend the extension configurations.
  *
  * @param ContainerBuilder $container
  */
 public function prepend(ContainerBuilder $container)
 {
     if ($container->hasExtension('sulu_search')) {
         $container->prependExtensionConfig('sulu_search', ['indexes' => ['contact' => ['security_context' => 'sulu.contact.people'], 'account' => ['security_context' => 'sulu.contact.organizations']]]);
     }
     if ($container->hasExtension('sulu_media')) {
         $container->prependExtensionConfig('sulu_media', ['system_collections' => ['sulu_contact' => ['meta_title' => ['en' => 'Sulu contacts', 'de' => 'Sulu Kontakte'], 'collections' => ['contact' => ['meta_title' => ['en' => 'People', 'de' => 'Personen']], 'account' => ['meta_title' => ['en' => 'Organizations', 'de' => 'Organisationen']]]]]]);
     }
 }