How to modify acme.adders.reverb.base.Adder for adding several environments' transitions in Acme?

I wanna use acme's algorithms to interact with the vectorized environments(just like `baselines.VectorEnv`), however maintaining N adders for N environments will decrease the efficiency when collecting samples and sending them to reverb_server(when I use my VecEnv(num_envs=64), sending transitions to replay buffer will use 60% time of the total sampling time). So how to modify the code of `acme.adders.reverb.base.Adder` and its subclasses to make it can add several environments' transitions in one adder?
Thank you very much~