code: def test_add_lambda_extension(self):
      dummy_class = DummyClass()
      self.trainer.extend(lambda x: dummy_class.touch())
      self.trainer.run()
      self.assertTrue(dummy_class.is_touched)
  
imports: import time
  import traceback
  import unittest
  from chainer import testing
  from chainer import training
label_desc: Use image node_id 8 for calling the TestTrainer obj's underlying member method code with example usage: obj.test_add_lambda_extension() without return types