code: def test_random(self):
      self.dataset.label_randomly(50)
      assert len(self.dataset) == 50
      assert len(self.dataset.pool) == 50
  
imports: import pickle
  import unittest
  import unittest.mock
  import warnings
  import datasets
  import numpy
  import pytest
  import torch.utils.data
  from torchvision.transforms import Lambda
  from baal.active import ActiveLearningDataset
label_desc: Use image node_id 9 for calling the ActiveDatasetTest obj's underlying member method code with example usage: obj.test_random() without return types