code: def app_ctx(app: Flask) -> t.Generator[AppContext, None, None]:
      with app.app_context() as ctx:
          yield ctx
  
file_path: flask-sqlalchemy/tests/conftest.py
imports: from __future__ import annotations
  import types
  import typing
  from pathlib import Path
  import pytest
  import sqlalchemy
  import sqlalchemy.orm
  from flask import Flask
  from flask.ctx import AppContext
  from flask_sqlalchemy import SQLAlchemy
  from flask_sqlalchemy.model import Model
label_desc: Use image node_id 2 for calling a global function with example usage: app_ctx(app) without return types