code: def _get_well_known_file():
      
      # TODO(orestica): Revisit this method once gcloud provides a better way
      # of pinpointing the exact location of the file.
      default_config_dir = os.getenv(_CLOUDSDK_CONFIG_ENV_VAR)
      if default_config_dir is None:
          if os.name == 'nt':
              try:
                  default_config_dir = os.path.join(os.environ['APPDATA'],
                                                    _CLOUDSDK_CONFIG_DIRECTORY)
              except KeyError:
                  # This should never happen unless someone is really
                  # messing with things.
                  drive = os.environ.get('SystemDrive', 'C:')
                  default_config_dir = os.path.join(drive, '\\',
                                                    _CLOUDSDK_CONFIG_DIRECTORY)
          else:
              default_config_dir = os.path.join(os.path.expanduser('~'),
                                                '.config',
                                                _CLOUDSDK_CONFIG_DIRECTORY)
  
      return os.path.join(default_config_dir, _WELL_KNOWN_CREDENTIALS_FILE)
docs: Get the well known file produced by command 'gcloud auth login'.