public function paintGroupEnd($message)
    {
        $node    = $this->_stack->pop();
        $current = $this->_stack->peek();
        if ($current) {
            if ($node->isFailed()) {
                $current->fail();
            }
            $current->putChild($node);
        } else {
            $this->_graph = $node;
        }
        parent::paintGroupEnd($message);
    }