private function add_to_parent_category_branch($category, $newnode, &$categoriesbranch) {

        foreach ($categoriesbranch as $key => $branch) {
            if (!empty($branch['categoryid']) && $branch['categoryid'] == $category->parent) {
                // It may be empty (if it does not contain courses and this is the first child cat).
                if (!isset($categoriesbranch[$key]['branches'])) {
                    $categoriesbranch[$key]['branches'] = [];
                }
                $categoriesbranch[$key]['branches'][] = $newnode;
                return true;
            }
            if (!empty($branch['branches'])) {
                $parent = $this->add_to_parent_category_branch($category, $newnode, $categoriesbranch[$key]['branches']);
                if ($parent) {
                    return true;
                }
            }
        }

        return false;
    }