public function getFolderParent()
    {
        if ($this->isRootFolder()) {
            return null;
        }

        $parents = $this->getParents($this->getSession()->getDefaultContext());

        // return the first element of the array
        $parent = reset($parents);

        if (!$parent instanceof FolderInterface) {
            return null;
        }

        return $parent;
    }