/**
* Adds a node to this node
*/
public function add(Varien_Data_Tree_Node $node)
{
$node->setParent($this->_container);
// Set the Tree for the node
if ($this->_container->getTree() instanceof Varien_Data_Tree) {
$node->setTree($this->_container->getTree());
}
$this->_nodes[$node->getId()] = $node;
return $node;
}