def METHOD_NAME() -> None:
    s_0 = switzerland[0]
    assert s_0 is not None and s_0.icao24 is not None
    diff = switzerland - s_0.icao24
    assert diff is not None
    assert s_0.icao24 not in diff.icao24
    diff = switzerland - ["EXS33W", "4009f9"]
    assert diff is not None
    assert {"EXS33W", "4009f9"} not in diff.icao24
    f_BAW585E = switzerland["BAW585E"]
    assert f_BAW585E is not None
    f_BAW881V = switzerland["BAW881V"]
    assert f_BAW881V is not None
    f_BAW84ZV = switzerland["BAW84ZV"]
    assert f_BAW84ZV is not None
    diff = switzerland - f_BAW585E
    assert diff is not None
    assert "BAW585E" not in diff.callsigns
    assert diff["4009f9"] is not None
    assert diff["4009f9"].callsign == {"BAW881V", "BAW84ZV"}
    assert len(f_BAW881V) + len(f_BAW84ZV) == len(diff["4009f9"])
    sw_id = switzerland.assign_id().eval()
    assert sw_id is not None
    flight = sw_id["500142"]
    assert flight is not None
    assert isinstance(flight.flight_id, set)
    assert flight.callsign == "T7STK"
    flight_deleted = sw_id["T7STK_1158"]
    assert flight_deleted is not None
    diff = sw_id - flight_deleted
    assert diff is not None
    assert diff["T7STK"] is not None
    assert diff["T7STK"].start >= flight_deleted.stop
    assert (sw_id - sw_id) is None
    diff = sw_id - diff
    assert diff is not None
    assert diff.icao24 == {"500142"}