public function getChildForPrincipal(array $principalInfo)
    {
        $owner = $principalInfo['uri'];
        $acl = [
            [
                'privilege' => '{DAV:}all',
                'principal' => '{DAV:}owner',
                'protected' => true,
            ],
        ];

        list(, $principalBaseName) = Uri\split($owner);

        $path = $this->storagePath.'/'.$principalBaseName;

        if (!is_dir($path)) {
            mkdir($path, 0777, true);
        }

        return new Collection(
            $path,
            $acl,
            $owner
        );
    }