docstr: validation process
docstr_tok: ["validation","process"]
code: def DRL_validation(self, model, test_data, test_env, test_obs):
      """validation process"""
      for _ in range(len(test_data.index.unique())):
          action, _states = model.predict(test_obs)
          test_obs, rewards, dones, info = test_env.step(action)
  
imports: from __future__ import annotations
  import time
  import numpy
  import pandas
  from stable_baselines3 import A2C
  from stable_baselines3 import DDPG
  from stable_baselines3 import PPO
  from stable_baselines3 import SAC
  from stable_baselines3 import TD3
  from stable_baselines3.common.callbacks import BaseCallback
  from stable_baselines3.common.noise import NormalActionNoise
  from stable_baselines3.common.noise import OrnsteinUhlenbeckActionNoise
  from stable_baselines3.common.vec_env import DummyVecEnv
  from finrl import config
  from finrl.meta.env_stock_trading.env_stocktrading import StockTradingEnv
  from finrl.meta.preprocessor.preprocessors import data_split
label_desc: Use image node_id 5 for calling the DRLEnsembleAgent obj's underlying member method code with example usage: obj.DRL_validation(model, test_data, test_env, test_obs) without return types