code: def test_observation_stack_init_from_yaml_config():
      """Pre-processor unit test"""
  
      # load config
      config = load_env_config(
          wrapper_module, "dummy_observation_stack_config_file.yml"
      )
  
      # init environment
      env = build_dummy_structured_environment()
      env = ObservationStackWrapper(
          env, **config["observation_stack_wrapper"]
      )
  
      # test application of wrapper
      assertion_routine(env)
  
file_path: maze/maze/test/core/wrappers/test_observation_stack_wrapper.py
imports: from copy import deepcopy
  import maze.test.core.wrappers
  from maze.core.wrappers.observation_stack_wrapper import ObservationStackWrapper
  from maze.test.shared_test_utils.config_testing_utils import load_env_config
  from maze.test.shared_test_utils.dummy_env.dummy_core_env import DummyCoreEnvironment
  from maze.test.shared_test_utils.dummy_env.dummy_maze_env import DummyEnvironment
  from maze.test.shared_test_utils.dummy_env.dummy_struct_env import DummyStructuredEnvironment
  from maze.test.shared_test_utils.dummy_env.space_interfaces.action_conversion.dict_discrete import DictDiscreteActionConversion
  from maze.test.shared_test_utils.dummy_env.space_interfaces.observation_conversion.dict import ObservationConversion
label_desc: Use image node_id 5 for calling a global function with example usage: test_observation_stack_init_from_yaml_config() without return types