class_docstr: Base class for logged, aka behavior, dataset
docstr: Args:
      idx: index of the sample
  
  Returns:
      tuple of features, action, and reward at idx
code: def __getitem__(self, idx) -> dataclass:
      """
      Args:
          idx: index of the sample
  
      Returns:
          tuple of features, action, and reward at idx
      """
      pass
  
file_path: ReAgent/reagent/ope/datasets/logged_dataset.py
imports: from abc import ABC, abstractmethod
  from dataclasses import dataclass
  import torch
label_desc: Use image node_id 2 for calling the BanditsDataset obj's underlying member method code with example usage: obj.__getitem__(idx) without return types