code: def _retrieve_connection_to_an_app() -> (
      Tuple[Optional[str], Optional[str]]
  ):
      connected_file = os.path.join(
          _LIGHTNING_CONNECTION_FOLDER, "connect.txt"
      )
      return _read_connected_file(connected_file)
  
imports: import json
  import os
  import shutil
  import sys
  from subprocess import Popen
  from typing import List, Optional, Tuple
  import click
  import psutil
  from lightning_utilities.core.imports import package_available
  from rich.progress import Progress
  from lightning.app.utilities.cli_helpers import _get_app_display_name, _LightningAppOpenAPIRetriever
  from lightning.app.utilities.cloud import _get_project
  from lightning.app.utilities.enum import OpenAPITags
  from lightning.app.utilities.log import get_logfile
  from lightning.app.utilities.network import LightningClient
label_desc: Use image node_id 4 for calling a global function with example usage: _retrieve_connection_to_an_app() and returns: _read_connected_file