docs: def list_config_files() -> List[Text]:
      """
      This function returns the list of configuration files to load.
  
      This is a callable so the configuration can be reloaded with files that
      changed in between.
      """
  
      return [
          os.path.join(os.path.dirname(__file__), 'default_settings.py'),
          os.getenv(ENVIRONMENT_VARIABLE, ''),
      ]