def undo(self):
        """
        Restore to last version
        """
        log = getLogger('ocrd.workspace_backup.undo')
        backups = self.list()
        if backups:
            last_backup = backups[0]
            self.restore(last_backup.chksum, choose_first=True)
        else:
            log.info("No backups, nothing to undo.")