Symfony\Component\Templating\PhpEngine::get PHP Метод

    public function get($name)
    {
        if (!isset($this->helpers[$name])) {
            throw new \InvalidArgumentException(sprintf('The helper "%s" is not defined.', $name));
        }

        return $this->helpers[$name];
    }

 protected function setTheme(FormView $view, array $themes)
 {
     $this->engine->get('form')->setTheme($view, $themes);
 }