code: def might_contain_dag_via_default_heuristic(
      file_path: str, zip_file: zipfile.ZipFile | None = None
  ) -> bool:
      """
      Heuristic that guesses whether a Python file contains an Airflow DAG definition.
  
      :param file_path: Path to the file to be checked.
      :param zip_file: if passed, checks the archive. Otherwise, check local filesystem.
      :return: True, if file might contain DAGs.
      """
      if zip_file:
          with zip_file.open(file_path) as current_file:
              content = current_file.read()
      else:
          if zipfile.is_zipfile(file_path):
              return True
          with open(file_path, "rb") as dag_file:
              content = dag_file.read()
      content = content.lower()
      return all(s in content for s in (b"dag", b"airflow"))
  
imports: from __future__ import annotations
  import ast
  import logging
  import os
  import zipfile
  from io import TextIOWrapper
  from pathlib import Path
  from typing import Generator, NamedTuple, Pattern, Protocol, overload
  import re2
  from pathspec.patterns import GitWildMatchPattern
  from airflow.configuration import conf
  from airflow.exceptions import RemovedInAirflow3Warning
label_desc: Use image node_id 12 for calling a global function with example usage: might_contain_dag_via_default_heuristic(file_path, zip_file) and returns: all, True