code: def test_yaml_writer_stories_to_yaml_with_null_entities(
      domain: Domain,
  ):
      writer = YAMLStoryWriter()
      stories = textwrap.dedent(
          """
      version: "{LATEST_TRAINING_DATA_FORMAT_VERSION}"
      stories:
      - story: happy path
        steps:
        - intent: test_intent
          entities:
          - test_entity: null
          - test_entity2: false
      """
      )
  
      stories_yaml = YAMLStoryReader().read_from_string(stories)
      result = writer.stories_to_yaml(stories_yaml)
      assert isinstance(result, OrderedDict)
      assert "stories" in result
      assert len(result["stories"]) == 1
      entities = result["stories"][0]["steps"][0]["entities"]
      assert entities[0] == "test_entity"
      assert entities[1] == OrderedDict({"test_entity2": False})
  
imports: from pathlib import Path
  import textwrap
  from typing import Text
  from collections import OrderedDict
  import pytest
  from rasa.shared.constants import LATEST_TRAINING_DATA_FORMAT_VERSION
  from rasa.shared.core.constants import ACTION_SESSION_START_NAME, ACTION_LISTEN_NAME, ACTION_UNLIKELY_INTENT_NAME
  from rasa.shared.core.domain import Domain
  from rasa.shared.core.events import ActionExecuted, UserUttered, DefinePrevUserUtteredFeaturization
  from rasa.shared.core.trackers import DialogueStateTracker
  from rasa.shared.core.training_data.story_reader.yaml_story_reader import YAMLStoryReader
  from rasa.shared.core.training_data.story_writer.yaml_story_writer import YAMLStoryWriter
  from rasa.shared.core.training_data.structures import STORY_START
label_desc: Use image node_id 6 for calling a global function with example usage: test_yaml_writer_stories_to_yaml_with_null_entities(domain) without return types