code: def test_load_optimizer_type(backend):
      """
      Test the _load_optimizer_config with just the `class_name` specified. In this case we expect a
      `tf.keras.optimizers.Optimizer` class to be returned.
      """
      class_name = "Adam"
      cfg_opt = {"class_name": class_name}
      optimizer = _load_optimizer_config(cfg_opt, backend=backend)
      assert isinstance(optimizer, type)
      assert optimizer.__name__ == class_name
  
file_path: alibi-detect/alibi_detect/saving/_tensorflow/tests/test_saving_tf.py
imports: from pytest_cases import param_fixture, parametrize, parametrize_with_cases
  import pytest
  from alibi_detect.saving.tests.datasets import ContinuousData
  from alibi_detect.saving.tests.models import encoder_model
  from alibi_detect.cd.tensorflow import HiddenOutput
  from alibi_detect.saving.loading import _load_model_config, _load_optimizer_config
  from alibi_detect.saving.saving import _path2str, _save_model_config, _save_optimizer_config
  from alibi_detect.saving.schemas import ModelConfig, SupportedOptimizer
  import tensorflow
  import numpy
  from packaging import version
label_desc: Use image node_id 3 for calling a global function with example usage: test_load_optimizer_type(backend) without return types