def test_bool(self):
        prio_set_list = event._PrioritizedSetList()

        assert bool(prio_set_list) is False

        prio_set_list.add(0, None)
        assert bool(prio_set_list) is True
def __init__(
        self, minimum=None, maximum=None, choices=None, optional=False
    ):
        self._required = not optional
        self._minimum = minimum
        self._maximum = maximum
        self._choices = choices