class_docstr: Used by split_dataset
code: def __getitem__(self, key):
      return self.underlying_dataset[self.keys[key]]
  
file_path: dowhy/dowhy/causal_prediction/dataloaders/misc.py
imports: import hashlib
  from collections import Counter
  import numpy
  import torch
label_desc: Use image node_id 2 for calling the _SplitDataset obj's underlying member method code with example usage: obj.__getitem__(key) and returns: self