code: def test_configure_optimizers_with_unknown_type(self, trainer):
      # Test unknown optimizer configuration. Return NotImplementedError.
      trainer._optimizer_params = {
          "type": "Unknown",
          "optim_params": {},
      }
      with pytest.raises(NotImplementedError) as excinfo:
          trainer.configure_optimizers()
          assert "Unknown optimizer type Unknown." in str(excinfo.value)
  
imports: import pytest
  import torch
  import torch.nn
  from torch.utils.data import DataLoader, TensorDataset
  from kale.embed.image_cnn import SimpleCNNBuilder
  from kale.pipeline.base_nn_trainer import BaseNNTrainer, CNNTransformerTrainer, MultimodalNNTrainer
  from kale.predict.class_domain_nets import ClassNet
label_desc: Use image node_id 8 for calling the TestBaseTrainer obj's underlying member method code with example usage: obj.test_configure_optimizers_with_unknown_type(trainer) without return types