code: def test_with_optimizer_none(self):
      model = Model(self.pytorch_network, None, self.loss_function)
      self.assertEqual(model.optimizer, None)
  
file_path: poutyne/tests/framework/model/test_model_optimizer.py
imports: import unittest
  import torch
  import torch.nn
  import torch.optim
  from poutyne import Model
label_desc: Use image node_id 2 for calling the ModelOptimizerInstanciationTest obj's underlying member method code with example usage: obj.test_with_optimizer_none() without return types