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 _try_write_with_flush(cls, fileobj, payload):
        """This method is here so that it can be patched to simulate write errors.

        This is because mock can't patch primitive objects like file objects.
        """
        fileobj.write(payload)
        fileobj.flush()