Can't start the SingleThreadedRunner again after closing it

[TorecLuik]

Hey,

I was trying out stopping and starting my (SingleThreadedRunner) runner but it fails.

The little test below raises this RunnerAlreadyStarted exception at the final runner.start() call (so after closing).
I think the close() of SingleThreadedRunner probably should reset that is_started variable?
Or is it not intended to work? at least the error is wrong then.

def test_runner():
    # Create a System instance with the necessary components
    system = System(pipes=[[WorkflowTracker, JobAccounting]])
    runner = SingleThreadedRunner(system)
    runner.start()

    # Get the application
    wft = runner.get(WorkflowTracker)

    # when
    assert wft.closing.is_set() is False
    runner.stop()
    assert wft.closing.is_set() is True
    
    runner.start()
    wft2 = runner.get(WorkflowTracker)
    assert wft2.closing.is_set() is False
    

        if self.is_started:
>           raise RunnerAlreadyStarted()
E           eventsourcing.system.RunnerAlreadyStarted