void assertStopped() {
        assertHasState(Stopped)
    }

    @Override
    void assertCanceled() {
        assertHasState(Canceled)
    }

    @Override
    DaemonFixture becomesCanceled() {
        waitForState(Canceled)
        this
    }

    protected abstract void waitForState(State state)

    protected abstract void assertHasState(State state)

    @Override