code: def test_get_core_nlu_files(project):
      data_dir = os.path.join(project, "data")
      nlu_files = rasa.shared.data.get_data_files(
          [data_dir], rasa.shared.data.is_nlu_file
      )
      core_files = rasa.shared.data.get_data_files(
          [data_dir], YAMLStoryReader.is_stories_file
      )
      assert len(nlu_files) == 1
      assert list(nlu_files)[0].endswith("nlu.yml")  # noqa: RUF015
  
      assert len(core_files) == 2
      assert any(file.endswith("stories.yml") for file in core_files)
      assert any(file.endswith("rules.yml") for file in core_files)
  
file_path: rasa/tests/shared/test_data.py
imports: import os
  import tempfile
  from pathlib import Path
  import pytest
  import rasa.shared
  import rasa.shared.data
  from rasa.shared.nlu.training_data.loading import load_data
  from rasa.shared.utils.io import write_text_file, json_to_string
  from rasa.shared.core.training_data.story_reader.yaml_story_reader import YAMLStoryReader
label_desc: Use image node_id 6 for calling a global function with example usage: test_get_core_nlu_files(project) without return types