code: def app():
      app = Flask("flask_test", root_path=os.path.dirname(__file__))
      app.config.update(
          TESTING=True,
          SECRET_KEY="test key",
      )
      return app
  
file_path: flask/tests/conftest.py
imports: import os
  import pkgutil
  import sys
  import pytest
  from _pytest import monkeypatch
  from flask import Flask
  from flask.globals import request_ctx
label_desc: Use image node_id 3 for calling a global function with example usage: app() and returns: app