def METHOD_NAME(path=None):
    """
    Save the latest two seasons of data for all locations, separately for each
    location tier (i.e. national, HHS, census, and states).
    """
    # set up the session
    sess = requests.session()
    sess.headers.update(
        {
            # it's polite to self-identify this "bot"
            "User-Agent": "delphibot/1.0 (+https://delphi.cmu.edu/)",
        }
    )
    # get metatdata
    print("looking up ilinet metadata")
    data = fetch_metadata(sess)
    info = get_issue_and_locations(data)
    issue = info["epiweek"]
    print(f"current issue: {int(issue)}")
    # establish timing
    dt = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
    current_season = info["season_id"]
    seasons = [s for s in range(current_season - 1, current_season + 1)]
    # make the destination path if it doesn't already exist
    if path is not None:
        os.makedirs(path, exist_ok=True)
    # download the data file for each tier
    files = []
    for delphi_name, cdc_name in (
        ("nat", Key.TierType.nat),
        ("hhs", Key.TierType.hhs),
        ("cen", Key.TierType.cen),
        ("sta", Key.TierType.sta),
    ):
        name = f"ilinet_{delphi_name}_{int(issue)}_{dt}.zip"
        if path is None:
            filename = name
        else:
            filename = os.path.join(path, name)
        tier_id = info["tier_ids"][cdc_name]
        locations = info["location_ids"][cdc_name]
        # download and show timing information
        print(f"downloading {delphi_name}")
        t0 = time.time()
        size = download_data(tier_id, locations, seasons, filename)
        t1 = time.time()
        print(f" saved {filename} ({int(size)} bytes in {t1 - t0:.1f} seconds)")
        files.append(filename)
    # return the current issue and the list of downloaded files
    return issue, files