public function getAcl($node)
    {
        if (is_string($node)) {
            $node = $this->server->tree->getNodeForPath($node);
        }
        if (!$node instanceof IACL) {
            return $this->getDefaultAcl();
        }
        $acl = $node->getACL();
        foreach ($this->adminPrincipals as $adminPrincipal) {
            $acl[] = [
                'principal' => $adminPrincipal,
                'privilege' => '{DAV:}all',
                'protected' => true,
            ];
        }

        return $acl;
    }