/**
  * Inject helpers into the View
  *
  * In each case, injects with the custom url/serverurl implementations.
  *
  * @param View $renderer
  * @param ContainerInterface $container
  */
 private function injectHelpers(View $renderer, ContainerInterface $container)
 {
     $helpers = $renderer->getHelpers();
     $helpers->set('url', function () use($container) {
         if (!$container->has(UrlHelper::class)) {
             throw new Exception\MissingHelperException(sprintf('An instance of %s is required in order to create the "url" view helper; not found', UrlHelper::class));
         }
         return $container->get(UrlHelper::class);
     });
     $helpers->set('serverurl', function () use($container) {
         if (!$container->has(ServerUrlHelper::class)) {
             throw new Exception\MissingHelperException(sprintf('An instance of %s is required in order to create the "url" view helper; not found', ServerUrlHelper::class));
         }
         return $container->get(ServerUrlHelper::class);
     });
 }