async def METHOD_NAME(c, s, a, b):
    class Bad(SchedulerPlugin):
        def transition(self, key, start, finish, **kwargs):
            raise Exception()
    bad = Bad()
    s.add_plugin(bad)
    x = c.submit(inc, 1)
    y = c.submit(inc, x)
    result = await y
    assert result == 3