public function visit(\DOMAttr $att, Compiler $context)
{
$node = $att->ownerElement;
$pi = $context->createControlNode("block " . $att->value);
$node->parentNode->insertBefore($pi, $node);
$pi = $context->createControlNode("endblock");
$node->parentNode->insertBefore($pi, $node->nextSibling);
$node->removeAttributeNode($att);
}