def METHOD_NAME(self, path_string: str) -> str:
    """
    Inputs:
        path_string: a string containing drive_name a colon and one or more folders like:
                     'my_drive:folder1/folder2'
    returns an ID string which can be used in a Google Drive URL
    """
    drive, folders = parse_path(path_string)
    assert isinstance(folders, list)
    assert isinstance(folders[:-1], list)
    all_but_last = f"{drive}:{'/'.join(folders[:-1])}"
    command_list = [self.rclone_path, "lsjson", "--dirs-only", all_but_last]
    try:
        result = subprocess.check_output(command_list, text=True)
    except subprocess.CalledProcessError as err:
        logger.exception(err)
        raise err
    returned_folders = json.loads(result)
    for folder in returned_folders:
        if folder["Name"] == folders[-1]:
            return folder["ID"]
    raise FileNotFoundError(f"Could not find a file or folder at {path_string}")