PHP Nested set to multidimensional array

gistfile1.txt

private function _formatTreeIntoArray(&$tree, $current_depth = 0)
    {
        $formattedTree = array();
        while($leaf = current($tree))
        {
            if($leaf->DEPTH > $current_depth)
            {
                $formattedTree[] = $this->_formatTreeIntoArray($tree, $leaf->DEPTH);
            }
            elseif($leaf->DEPTH < $current_depth)
            {
                return $formattedTree;
            }
            else
            {
                $formattedTree[] = $leaf;
                next($tree);
            }
        }

        return $formattedTree;
    }