code: def __len__(self):
      return 10
  
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 2 for calling the MyDataset obj's underlying member method code with example usage: obj.__len__() and returns: int