class_docstr: Statistics of a experiment.
  
  Args:
      total_epoch (int): Total epoches.
      total_itr (int): Total Iterations.
      total_env_steps (int): Total environment steps collected.
      last_episode (list[dict]): Last sampled episodes.
code: def __init__(
      self, total_epoch, total_itr, total_env_steps, last_episode
  ):
      self.total_epoch = total_epoch
      self.total_itr = total_itr
      self.total_env_steps = total_env_steps
      self.last_episode = last_episode
  
imports: import copy
  import os
  import time
  import cloudpickle
  from dowel import logger, tabular
  from garage.experiment.deterministic import get_seed, set_seed
  from garage.experiment.experiment import dump_json
  from garage.experiment.snapshotter import Snapshotter
label_desc: Use image node_id 1 to create a new ExperimentStats object  with example: obj = ExperimentStats(total_epoch, total_itr, total_env_steps, last_episode)