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 _getN(self, n):
        n -= 1
        p = self.head
        while n:
            p = p.next
            n -= 1
        return p