code: def test_classy_output_stateful(self):
      # confirm model.output keeps input data and that output == data
      output = self._model_stateful.forward(self._data)
      self.assertTrue(torch.equal(self._model_stateful.output, output))
      self.assertTrue(torch.equal(output, self._data))
  
file_path: ClassyVision/test/models_classy_block_stateless_test.py
imports: import os
  import unittest
  import torch
  from classy_vision.models import ClassyBlock
label_desc: Use image node_id 4 for calling the TestClassyStatelessBlock obj's underlying member method code with example usage: obj.test_classy_output_stateful() without return types