def METHOD_NAME(self, mapping, timeout=None):
    timeout = self._normalize_timeout(timeout)
    # Use transaction=False to batch without calling redis MULTI
    # which is not supported by twemproxy
    pipe = self._write_client.pipeline(transaction=False)
    for key, value in iteritems_wrapper(mapping):
        dump = self.dump_object(value)
        if timeout == -1:
            pipe.set(name=self.key_prefix + key, value=dump)
        else:
            pipe.setex(name=self.key_prefix + key, value=dump, time=timeout)
    return pipe.execute()