docstr: Test to make sure callbacks config dict works.
docstr_tok: ["Test","to","make","sure","callbacks","config","dict","works","."]
code: def test_update_from_dict_works_for_multi_callbacks(self):
      """Test to make sure callbacks config dict works."""
      config_dict = {"callbacks": make_multi_callbacks([])}
      config = AlgorithmConfig()
      # This should work.
      config.update_from_dict(config_dict)
  
      serialized = config.serialize()
  
      # For now, we don't support serializing make_multi_callbacks.
      # It'll turn into a classpath that's not really usable b/c the class
      # was created on-the-fly.
      self.assertEqual(
          serialized["callbacks"],
          "ray.rllib.algorithms.callbacks.make_multi_callbacks.<locals>."
          "_MultiCallbacks",
      )
  
imports: import gymnasium
  from typing import Type
  import unittest
  import ray
  from ray.rllib.algorithms.algorithm_config import AlgorithmConfig
  from ray.rllib.algorithms.callbacks import make_multi_callbacks
  from ray.rllib.algorithms.ppo import PPO, PPOConfig
  from ray.rllib.algorithms.ppo.tf.ppo_tf_learner import PPOTfLearner
  from ray.rllib.algorithms.ppo.torch.ppo_torch_rl_module import PPOTorchRLModule
  from ray.rllib.core.rl_module.rl_module import SingleAgentRLModuleSpec, RLModule
  from ray.rllib.core.rl_module.marl_module import MultiAgentRLModuleSpec, MultiAgentRLModule
  from ray.rllib.utils.test_utils import check
label_desc: Use image node_id 4 for calling the TestAlgorithmConfig obj's underlying member method code with example usage: obj.test_update_from_dict_works_for_multi_callbacks() without return types