public function getRootFolder(OperationContextInterface $context = null)
    {
        $rootFolderId = $this->getRepositoryInfo()->getRootFolderId();

        $rootFolder = $this->getObject(
            $this->createObjectId($rootFolderId),
            $context === null ? $this->getDefaultContext() : $context
        );

        if (!($rootFolder instanceof FolderInterface)) {
            throw new CmisRuntimeException('Root folder object is not a folder!', 1423735889);
        }

        return $rootFolder;
    }