code: def __getitem__(self, item):
      if isinstance(item, int):
          return {
              "sentence": self.dataset["sentence"][item],
              "label": self.dataset["label"][item],
          }
      elif isinstance(item, str):
          return self.dataset[item]
  
imports: import unittest
  import pytest
  from torch.utils.data import Dataset
  from transformers import AutoTokenizer
  from baal.active.dataset import ActiveLearningDataset
  from baal.active.dataset.nlp_datasets import HuggingFaceDatasets
  import datasets
label_desc: Use image node_id 3 for calling the MyDataset obj's underlying member method code with example usage: obj.__getitem__(item) and returns: dict, self