code: def __getitem__(self, index):
      if self.index_only:
          return index
      return 1, 2, index
  
file_path: MONAI/tests/test_zipdataset.py
imports: from __future__ import annotations
  import unittest
  import torch
  from parameterized import parameterized
  from monai.data import ZipDataset
label_desc: Use image node_id 3 for calling the Dataset_ obj's underlying member method code with example usage: obj.__getitem__(index) and returns: int,  int,  index, index