public function getRoot($categoryId)
    {
        $category = CategoryQuery::create()->findPk($categoryId);

        if (0 !== $category->getParent()) {
            $parentCategory = CategoryQuery::create()->findPk($category->getParent());

            if (null !== $parentCategory) {
                $categoryId = $this->getRoot($parentCategory->getId());
            }
        }

        return $categoryId;
    }