code: def test_scale_reward(env_id, scale):
      env = pfrl.wrappers.ScaleReward(gym.make(env_id), scale=scale)
      assert env.original_reward is None
      np.testing.assert_allclose(env.scale, scale)
  
      _ = env.reset()
      _, r, _, _ = env.step(env.action_space.sample())
  
      if env_id == "CartPole-v1":
          # Original reward must be 1
          np.testing.assert_allclose(env.original_reward, 1)
          np.testing.assert_allclose(r, scale)
      elif env_id == "MountainCar-v0":
          # Original reward must be -1
          np.testing.assert_allclose(env.original_reward, -1)
          np.testing.assert_allclose(r, -scale)
      else:
          assert False
  
imports: import gym
  import numpy
  import pytest
  import pfrl
label_desc: Use image node_id 1 for calling a global function with example usage: test_scale_reward(env_id, scale) without return types