code: def save_model(self):
      self.agent.save(self.model)
  
      with open(self.model.replace(".pth", ".json"), "w") as f:
          data = {
              "current_episode": self.current_episode,
              "current_step": self.current_step,
          }
  
          f.write(json.dumps(data))
  
imports: from serpent.machine_learning.reinforcement_learning.agent import Agent
  from serpent.game_frame import GameFrame
  from serpent.game_frame_buffer import GameFrameBuffer
  from serpent.input_controller import KeyboardEvent, MouseEvent
  from serpent.enums import InputControlTypes
  from serpent.logger import Loggers
  from serpent.utilities import SerpentError
  import os
  import io
  import enum
  import random
  import json
  import numpy
  import h5py
  import skimage.io
  import skimage.util
label_desc: Use image node_id 6 for calling the RainbowDQNAgent obj's underlying member method code with example usage: obj.save_model() without return types