code: def save(self, filename):
      with open(filename, "wb") as f:
          pickle.dump((self.memory, self.episodic_memory), f)
  
file_path: chainerrl/chainerrl/replay_buffers/episodic.py
imports: import collections
  import pickle
  from chainerrl.misc.collections import RandomAccessQueue
  from chainerrl.replay_buffer import AbstractEpisodicReplayBuffer
  from chainerrl.replay_buffer import random_subseq
label_desc: Use image node_id 7 for calling the EpisodicReplayBuffer obj's underlying member method code with example usage: obj.save(filename) without return types