def open(self, name, mode='r', namespace=None):
        if mode not in ('r', 'l'):
            raise NotImplementedError('TBD later!')

        if mode == 'l':
            return defer.maybeDeferred(self._open_live, namespace, name)
        elif mode != 'r':
            return defer.maybeDeferred(self._open_readable, namespace, name)
dataset/ETHPy150Open arkadini/twimp/twimp/server/inmemory.py/IMServer.open/operator `==` -> `!=`