code: def __getitem__(self, i):
      return {"input_ids": self.x, "labels": self.x}
  
file_path: baal/tests/transformers_trainer_wrapper_test.py
imports: import unittest
  from copy import deepcopy
  import numpy
  import pytest
  import torch
  from transformers import GPT2LMHeadModel, GPT2Config
  from transformers import TrainingArguments
  from baal.transformers_trainer_wrapper import BaalTransformersTrainer
label_desc: Use image node_id 3 for calling the DummyDataset obj's underlying member method code with example usage: obj.__getitem__(i) and returns: dict