code: def test_dataset(self):
      assert len(self.active_dataset) == 0
      self.active_dataset.label_randomly(2)
      assert len(self.active_dataset) == 2
  
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 ActiveArrowDatasetTest obj's underlying member method code with example usage: obj.test_dataset() without return types