code: def _iter_envs():
      for env_name in gym.envs.registry:
          if env_name.startswith(bandit.envs.RIVER_NAMESPACE):
              yield gym.make(env_name)
  
imports: from __future__ import annotations
  import gym.utils.env_checker
  import pytest
  from river import bandit
label_desc: Use image node_id 1 for calling a global function with example usage: _iter_envs() without return types