code: def test_cast_observation_to_float32(env_id):
      env = pfrl.wrappers.CastObservationToFloat32(gym.make(env_id))
  
      obs = env.reset()
      assert env.original_observation.dtype == np.float64
      assert obs.dtype == np.float32
      np.testing.assert_allclose(env.original_observation, obs)
  
      obs, r, done, info = env.step(env.action_space.sample())
      assert env.original_observation.dtype == np.float64
      assert obs.dtype == np.float32
      np.testing.assert_allclose(env.original_observation, obs)
  
imports: import gym
  import numpy
  import pytest
  import pfrl
label_desc: Use image node_id 2 for calling a global function with example usage: test_cast_observation_to_float32(env_id) without return types