code: def __call__(self, trainer):
      self._test_case.assertTrue(trainer.is_initialized)
      self.is_called = True
  
imports: import time
  import traceback
  import unittest
  from chainer import testing
  from chainer import training
label_desc: Use image node_id 2 for calling the DummyCallableClass obj's underlying member method code with example usage: obj.__call__(trainer) without return types