code/Debug/Block/View.php
public function getBlockTreeHtml()
    {
        $content = '';
        $rootNodes = $this->getBlocksAsTree();

        // Try to iterate our non-conventional tree
        foreach ($rootNodes as $rootNode) {
            $content .= $this->renderTreeNode($rootNode);
        }

        return $content;
    }
public function getBlockTreeHtml()
    {
        $content = '';
        $rootNodes = $this->getBlocksAsTree();

        // Try to iterate our non-conventional tree
        foreach ($rootNodes as $rootNode) {
            $content .= $this->renderTreeNode($rootNode);
        }

        return $content;
    }
Returns a tree html representation for layout tree

@return string