def METHOD_NAME():
    # The end of this timeseries is (in 1000s) ... 127, 126, 127, 127. Ony the last 127 is
    # expected to be truncated.
    values = list(range(100_000, 128_000, 1_000)) + [126_000, 127_000, 127_000]
    assert len(values) == 31
    ds_in = test_helpers.build_default_region_dataset({CommonFields.CASES: values})
    tail_filter, ds_out = TailFilter.run(ds_in, [CommonFields.CASES])
    ds_expected = test_helpers.build_default_region_dataset({CommonFields.CASES: values[:-1]})
    _assert_tail_filter_counts(tail_filter, truncated=1)
    test_helpers.assert_dataset_like(ds_out, ds_expected, drop_na_dates=True, compare_tags=False)