Symfony4：无法加载“ Symfony \ Component \ Form \ FormRenderer”

Question

作为Symfony和Twig的新手，我尝试使用Symfony Form和Twig作为渲染引擎来构建表单。

不使用Symfony应用程序，仅使用4. *组件

我使用了本教程

https://symfony.com/doc/current/components/form.html

    $twig = new Environment(
        new FilesystemLoader(
            [
                VIEWS_DIR,
                VENDOR_TWIG_BRIDGE_DIR . '/Resources/views/Form',
            ]
        )
    );
    $formEngine = new TwigRendererEngine(
        [DEFAULT_FORM_THEME],
        $twig);

    $twig->addExtension(new TranslationExtension($translator));

    $the_renderer = new FormRenderer($formEngine, $csrfTokenManager);
    $form_extension = new FormExtension($the_renderer);

    $twig->addExtension(
        $form_extension
    );

但是，打电话时

$twig_environment->render(
            'form/basic_form.html.twig',
            ['form' => $form->createView()]
);

错误

Uncaught Twig\Error\RuntimeError: Unable to load the "Symfony\Component\Form\FormRenderer"

我读过，Symfony从TwigRenderer更改为FormRenderer，而且我看到有解决方案，例如Silex

如何为Symfony4组件解决此问题？