public function displayParentBlock($name, array $context, array $blocks = array())
    {
        $name = (string) $name;

        if (isset($this->traits[$name])) {
            $this->traits[$name][0]->displayBlock($name, $context, $blocks);
        } elseif (false !== $parent = $this->getParent($context)) {
            $parent->displayBlock($name, $context, $blocks);
        } else {
            throw new Twig_Error_Runtime(sprintf('The template has no parent and no traits defining the "%s" block', $name), -1, $this->getTemplateName());
        }
    }