code: def test_observation_normalization_init_from_yaml_config():
      """observation normalization test"""
  
      # load config
      config = load_env_config(
          test_observation_normalization_module, "dummy_config_file.yml"
      )
  
      # init environment
      env = GymMazeEnv("CartPole-v0")
      env = ObservationNormalizationWrapper(
          env, **config["observation_normalization_wrapper"]
      )
      assert isinstance(env, ObservationNormalizationWrapper)
  
      stats = env.get_statistics()
      assert (
          "stat_1" in stats["observation"]
          and "stat_2" in stats["observation"]
      )
  
      norm_strategies = getattr(env, "_normalization_strategies")
      strategy = norm_strategies["observation"]
      assert isinstance(strategy, ObservationNormalizationStrategy)
      assert strategy._clip_min == 0
      assert strategy._clip_max == 1
      assert np.all(
          strategy._statistics["stat_1"] == np.asarray([0, 0, 0, 0])
      )
      assert np.all(
          strategy._statistics["stat_2"] == np.asarray([1, 1, 1, 1])
      )
  
imports: import copy
  import os
  import numpy
  import pytest
  import maze.test.core.wrappers.observation_normalization
  from maze.core.agent.random_policy import RandomPolicy
  from maze.core.env.structured_env import ActorID
  from maze.core.log_stats.log_stats import register_log_stats_writer, increment_log_step
  from maze.core.log_stats.log_stats_writer_console import LogStatsWriterConsole
  from maze.core.log_stats.log_stats_writer_tensorboard import LogStatsWriterTensorboard
  from maze.core.wrappers.log_stats_wrapper import LogStatsWrapper
  from maze.core.wrappers.maze_gym_env_wrapper import GymMazeEnv
  from maze.core.wrappers.observation_normalization.normalization_strategies.base import ObservationNormalizationStrategy
  from maze.core.wrappers.observation_normalization.observation_normalization_utils import obtain_normalization_statistics
  from maze.core.wrappers.observation_normalization.observation_normalization_wrapper import ObservationNormalizationWrapper
  from maze.test.shared_test_utils.config_testing_utils import load_env_config
label_desc: Use image node_id 8 for calling a global function with example usage: test_observation_normalization_init_from_yaml_config() without return types