public function parse(\Twig_NodeInterface $node)
    {
        foreach ($node as $subNode) {

            if (! $subNode instanceof \Twig_NodeInterface) {
                continue;
            }

            $nodeClass = get_class($subNode);

            switch ($nodeClass) {
                case 'Twig_Node_Set':
                    $this->context[] = $this->env->getCompiler()->compile($subNode)->getSource();
                    break;
                
                default:
                    $this->parse($subNode);
                    break;
            }
        }

        return $this;
    }