code: def reset(self):
      if self.iterator is None:
          self.iterator = iter(self.loader)
      try:
          self.current_sample, self.step_count = next(self.iterator)
          self.current_step = 0
          return self.current_sample
      except StopIteration:
          self.iterator = None
          return generate_nan_observation(self.observation_space)
  
imports: from collections import Counter
  import gym
  import numpy
  from tianshou.data import Batch, Collector
  from tianshou.policy import BasePolicy
  from torch.utils.data import DataLoader, Dataset, DistributedSampler
  from qlib.rl.utils.finite_env import LogWriter, FiniteDummyVectorEnv, FiniteShmemVectorEnv, FiniteSubprocVectorEnv, check_nan_observation, generate_nan_observation
label_desc: Use image node_id 2 for calling the FiniteEnv obj's underlying member method code with example usage: obj.reset() and returns: self, generate_nan_observation