code: def _iter_policies():
      for _, policy in inspect.getmembers(
          importlib.import_module("river.bandit"), inspect.isclass
      ):
          for params in policy._unit_test_params():
              yield policy(**params)
  
file_path: river/river/bandit/test_policies.py
imports: from __future__ import annotations
  import copy
  import importlib
  import inspect
  import random
  import gym
  import pytest
  from river import bandit, metrics
  from .test_envs import _iter_envs
label_desc: Use image node_id 2 for calling a global function with example usage: _iter_policies() without return types