code: def test_init(self):
      strategy = ExpectedGradientLength(4, batch_size=100, device="cpu")
  
      self.assertEqual(4, strategy.num_classes)
      self.assertEqual(100, strategy.batch_size)
      self.assertEqual("cpu", strategy.device)
  
file_path: small-text/tests/unit/small_text/integrations/pytorch/test_strategies.py
imports: import unittest
  import pytest
  import numpy
  from small_text.integrations.pytorch.exceptions import PytorchNotFoundError
label_desc: Use image node_id 2 for calling the ExpectedGradientLengthTest obj's underlying member method code with example usage: obj.test_init() without return types