code: def test_with_optimizer(self):
      optimizer = mock.Mock()
      optimizer.x = 0
      extension = extensions.WarmupShift(
          "x", self.warmup_start, self.warmup_iter, self.init, optimizer
      )
      self._run_trainer(extension, self.expect, optimizer)
  
file_path: chainer/tests/chainer_tests/training_tests/extensions_tests/test_warmup_shift.py
imports: import unittest
  import mock
  from chainer import testing
  from chainer.training import extensions
  from chainer.training import util
label_desc: Use image node_id 5 for calling the TestWarmupShift obj's underlying member method code with example usage: obj.test_with_optimizer() without return types