def METHOD_NAME(testdataset1: Dataset):
    """Test that an occupancy with the same start but no end, and one with the
    same end but no start, don't end up with the same ID. This occurs in the wild
    when a source has an unknown start date, ends a term, then starts the next
    term."""
    context = Context(testdataset1)
    pos = make_position(context, name="A position", country="ls")
    person = context.make("Person")
    person.id = "thabo"
    def make(implies, start, end):
        return make_occupancy(
        context, person, pos, implies, datetime(2021, 1, 1), start, end
    )
    current_no_end = make(True, "2020-01-01", None)
    assert current_no_end.get("status") == ["current"]
    ended_no_start = make(True, None, "2020-01-01")
    assert ended_no_start.get("status") == ["ended"]
    assert ended_no_start.id != current_no_end.id