Store the model in Redis.

        :rtype: bool

def save(self):
        """Store the model in Redis.

        :rtype: bool

        """
        pipeline = self._redis_client.pipeline()
        pipeline.set(self._key, base64.b64encode(self.dumps()))
        if self._ttl:
            pipeline.expire(self._key, self._ttl)
        result = yield gen.Task(pipeline.execute)
        self._dirty, self._saved = not all(result), all(result)
        raise gen.Return(all(result))