code: def __call__(self, study: optuna.study, frozen_trial: optuna.Trial):
      # Setting the best value in the current trial
      study.set_user_attr("previous_best_value", study.best_value)
  
      # Checking if the minimum number of trials have pass
      if frozen_trial.number > self.trial_number:
          previous_best_value = study.user_attrs.get(
              "previous_best_value", None
          )
          # Checking if the previous and current objective values have the same sign
          if previous_best_value * study.best_value >= 0:
              # Checking for the threshold condition
              if (
                  abs(previous_best_value - study.best_value)
                  < self.threshold
              ):
                  self.cb_list.append(frozen_trial.number)
                  # If threshold is achieved for the patience amount of time
                  if len(self.cb_list) > self.patience:
                      print("The study stops now...")
                      print(
                          "With number",
                          frozen_trial.number,
                          "and value ",
                          frozen_trial.value,
                      )
                      print(
                          "The previous and current best values are {} and {} respectively".format(
                              previous_best_value, study.best_value
                          )
                      )
                      study.stop()
  
imports: from __future__ import annotations
  import datetime
  import joblib
  import optuna
  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
  import finrl.agents.stablebaselines3.hyperparams_opt
  from finrl import config
  from finrl.agents.stablebaselines3.models import DRLAgent
  from finrl.main import check_and_make_directories
  from finrl.plot import backtest_stats
label_desc: Use image node_id 2 for calling the LoggingCallback obj's underlying member method code with example usage: obj.__call__(study, frozen_trial) without return types