code: def test_step_args(self):
      opt = build_optimizer(self._get_config())
      opt.set_param_groups([torch.tensor([1.0], requires_grad=True)])
  
      # where argument must be named explicitly
      with self.assertRaises(RuntimeError):
          opt.step(0)
  
      # this shouldn't crash
      opt.step(where=0)
  
imports: from abc import ABC, abstractmethod
  from unittest.mock import MagicMock
  import torch
  import torch.nn
  from classy_vision.generic.util import split_batchnorm_params
  from classy_vision.models import ClassyModel
  from classy_vision.optim import build_optimizer, build_optimizer_schedulers
  from classy_vision.optim.param_scheduler import LinearParamScheduler
label_desc: Use image node_id 13 for calling the TestOptimizer obj's underlying member method code with example usage: obj.test_step_args() without return types