def get_last_tid(self):
        try:
            spec = {'tid': {'$gt': 0}}
            sort = [('tid', -1)]
            row = self.db.docs.find_one(spec, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return row['tid']
        return 0
def setLDAPDirectory(self, directory=None):
        if directory is None:
                self.directory = []
        else:
            try:
                with open(DIRECTORY, 'w+') as f:
                    f.write(str(directory))
                    self.directory = directory
            except OSError as e:
                raise