code: def optimizer_dummy(self):
      from torch.optim import Optimizer
  
      optim = Mock(spec=Optimizer)
      optim.param_groups = [
          {"lr": 0.01, "momentum": 0.9},
          {"lr": 0.02, "momentum": 0.9},
      ]
      return optim
  
file_path: skorch/skorch/tests/test_setter.py
imports: from unittest.mock import Mock
  import pytest
label_desc: Use image node_id 2 for calling the TestOptimizerSetter obj's underlying member method code with example usage: obj.optimizer_dummy() and returns: optim