class_docstr: Composes models from explicit model definitions.
  
  :param action_spaces_dict: Dict of sub-step id to action space.
  :param observation_spaces_dict: Dict of sub-step id to observation space.
  :param distribution_mapper_config: Distribution mapper configuration.
  :param policy: Mapping of sub-step keys to models.
  :param critic: Configuration for the critic composer.
docstr: Return the critic networks.
docstr_tok: ["Return","the","critic","networks","."]
code: def critic(
      self,
  ) -> Optional[Union[TorchStateCritic, TorchStateActionCritic]]:
      """Return the critic networks."""
      if self._critics_composer is None:
          return None
  
      return self._critics_composer.critic
  
imports: import copy
  from typing import Dict, Union, Optional, Mapping
  import gym
  import numpy
  from gym import spaces
  from maze.core.agent.state_critic_input_output import StateCriticStepInput
  from maze.core.agent.torch_policy import TorchPolicy
  from maze.core.agent.torch_state_action_critic import TorchStateActionCritic
  from maze.core.agent.torch_state_critic import TorchStateCritic
  from maze.core.annotations import override
  from maze.core.env.structured_env import StepKeyType, ActorID
  from maze.core.utils.factory import Factory, ConfigType
  from maze.perception.models.critics import BaseStateCriticComposer, SharedStateCriticComposer
  from maze.perception.models.critics.base_state_action_critic_composer import BaseStateActionCriticComposer
  from maze.perception.models.critics.critic_composer_interface import CriticComposerInterface
  from maze.perception.models.model_composer import BaseModelComposer
  from maze.perception.models.policies.base_policy_composer import BasePolicyComposer
  from maze.perception.perception_utils import map_nested_structure
label_desc: Use image node_id 5 for calling the CustomModelComposer obj's underlying member method code with example usage: obj.critic() and returns: self, None