code: def __getitem__(self, idx: int) -> int:
      return idx
  
imports: import math
  import unittest.mock
  from typing import Any, Dict, List, Optional
  import pytest
  import torch
  from torch.utils import data
  from determined import core, pytorch
  from determined.pytorch import experimental
  from tests.launch import test_util
label_desc: Use image node_id 3 for calling the IndexData obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: idx