public function getPublicRoots()
    {
        $roots = [];
        foreach ($this->filesystems->keys() as $ident) {
            if ($this->isFilesystemPublic($ident)) {
                $disk = $this->getNamedRoot($ident);
                if ($disk !== null) {
                    $roots[$ident] = $disk;
                }
            }
        }

        return $roots;
    }