class_docstr: Base class for logged, aka behavior, dataset
docstr: Returns:
      length of the dataset
code: def __len__(self) -> int:
      """
      Returns:
          length of the dataset
      """
      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 1 for calling the BanditsDataset obj's underlying member method code with example usage: obj.__len__() without return types