code: def __init__(self, config=None):
      super().__init__()
      self.observation_space = gym.spaces.Dict(
          {"agent0": gym.spaces.Box(-1.0, 1.0, (1,))}
      )
      self.action_space = gym.spaces.Dict(
          {"agent0": gym.spaces.Discrete(2)}
      )
      self._agent_ids = {"agent0"}
  
imports: import unittest
  import ray
  from ray.rllib.algorithms.ppo import PPOConfig
  from ray.rllib.env.multi_agent_env import MultiAgentEnv
  from ray.rllib.env.wrappers.multi_agent_env_compatibility import MultiAgentEnvCompatibility
  from ray.rllib.utils.gym import try_import_gymnasium_and_gym
  from ray.tune.registry import register_env
label_desc: Use image node_id 1 to create a new MultiAgentGymnasiumOldAPI object from inherited base classes: MultiAgentEnv with example: obj = MultiAgentGymnasiumOldAPI(config)