code: def test_sanitize_message_for_prompt_handles_none():
      assert sanitize_message_for_prompt(None) == ""
  
file_path: rasa/tests/utils/test_llm.py
imports: from rasa.shared.core.domain import Domain
  from rasa.shared.core.events import BotUttered, UserUttered
  from rasa.shared.core.trackers import DialogueStateTracker
  from rasa.utils.llm import sanitize_message_for_prompt, tracker_as_readable_transcript
label_desc: Use image node_id 5 for calling a global function with example usage: test_sanitize_message_for_prompt_handles_none() without return types