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