def METHOD_NAME():
    resolver_init()
    rng_templ, entry_templ = get_templates()
    ranges = []
    check_last_msg = False
    # transform data in zones files into RANGEs
    files = os.listdir()
    files.sort()
    for fn in files:
        if not fn.endswith('.db') or not fn.startswith('20'):
            continue
        ranges.append(generate_range(fn, rng_templ, entry_templ))
    # connect ranges
    for i in range(1, len(ranges)):
        ranges[i - 1].b = ranges[i].a - 1
    ranges[-1].b = 99999999999999
    # steps
    steps = []
    tstart = datetime.datetime(year=2017, month=7, day=1)
    if VARIANT == "unmanaged_key":
        tend = datetime.datetime(year=2017, month=7, day=21, hour=23, minute=59, second=59)
        check_last_msg = True
    else:
        tend = datetime.datetime(year=2017, month=12, day=31, hour=23, minute=59, second=59)
    tstep = datetime.timedelta(days=1)
    tcurr = tstart
    while tcurr < tend:
        id_prefix = tcurr.strftime('%Y%m%d')
        steps.append(generate_step_query(tcurr, id_prefix))
        if (check_last_msg is True and tcurr + tstep > tend):
            steps.append(generate_step_finish_msg(id_prefix))
        elif VARIANT == "unmanaged_key":
            steps.append(generate_step_nocheck(id_prefix))
        else:
            steps.append(generate_step_check(id_prefix))
        steps.append(generate_step_elapse(tstep, id_prefix))
        tcurr += tstep
    # generate output
    with open('keys/ds') as dsfile:
        tas = dsfile.read().strip()
    # constant RPL file header
    print("stub-addr: 2001:503:ba3e::2:30")
    for ta in tas.split('\n'):
        print ("trust-anchor: " + ta)
    print("""val-override-date: 20170701000000