async def METHOD_NAME(self):
    # check that running the callback twice does not throw an exception
    queue = TaskQueue()
    completed = []
    def done(complete: CompletedTask):
        assert not complete.exc_info
        completed.append(complete.task.result())
    task = queue.run(retval(1), done)
    await task
    queue.completed_task(task, done, None, {})
    assert completed == [1, 1]