def test_lookup(self):
        assert event.Priority.lookup(event.Priority.CORE) is event.Priority.CORE
        assert event.Priority.lookup(event.Priority.CORE.value) is event.Priority.CORE
        assert event.Priority.lookup(-12312412) == -12312412
def _getN(self, n):
        n -= 1
        p = self.head
        while n:
            p = p.next
            n -= 1
        return p