QueryEngine::walk

public function walk(array $filter = null, callable $callback = null, Node $node, $limit = 0, $direction = self::DIR_DOWN)
{
	if($limit > 0)
	{
		$this->limit = $limit;
	}
	else
	{
		$this->limit = null;
	}

	$this->deep = true;
	$this->direction = $direction;

	return $this->walkInternal($filter, $callback, $node, $callback, $direction);
}