final OutputEventListener listener = Mock(OutputEventListener.class)

        loggingManager.addOutputEventListener(listener)

        when:
        loggingManager.start();

        then:
        1 * loggingRouter.addOutputEventListener(listener)

        when:
        loggingManager.stop()

        then:
        loggingManager.removeOutputEventListener(listener)

            loggingOutput.removeStandardErrorListener(listener);
        }
    }

    @Override
    public void addOutputEventListener(OutputEventListener listener) {
        if (outputEventListeners.add(listener) && started) {
            loggingOutput.addOutputEventListener(listener);
        }
    }

    @Override
    public void removeOutputEventListener(OutputEventListener listener) {

        LogEvent ignored = event('ignored', LogLevel.DEBUG)
        LogEvent event = event('message', LogLevel.INFO)

        when:
        renderer.configure(LogLevel.INFO)
        renderer.addOutputEventListener(listener)
        renderer.onOutput(ignored)
        renderer.onOutput(event)

        then:
        1 * listener.onOutput({ it instanceof LogLevelChangeEvent && it.newLogLevel == LogLevel.INFO })

        listenerManager.addListener(stopSessionScopeWorkers);
        this.logLevelChangeEventListener = new LogLevelChangeEventListener();
        loggingManager.addOutputEventListener(logLevelChangeEventListener);
        this.currentLogLevel = loggingManager.getLevel();
        this.memoryManager = memoryManager;

        WorkerLoggingProtocol workerLoggingProtocol = connection.addOutgoing(WorkerLoggingProtocol.class);
        workerLogEventListener.setWorkerLoggingProtocol(workerLoggingProtocol);
        loggingManager.addOutputEventListener(workerLogEventListener);
    }

    private void configureWorkerJvmMemoryInfoEvents(WorkerServices services, ObjectConnection connection) {

        def client = Mock(WorkerDaemonClient) {
            isCompatibleWith(_) >> true
            getLogLevel() >> LogLevel.INFO
        }
        starter.startDaemon(options) >> client
        loggingManager.addOutputEventListener(_) >> { args -> listener = args[0] }
        loggingManager.getLevel() >> LogLevel.INFO

        when:

            if (stdErrListener != null) {
                removeChain(stdErrListener);
                stdErrListener = null;
            }
        }
    }

    @Override
    public void addOutputEventListener(OutputEventListener listener) {
        synchronized (lock) {
            addChain(listener);
        }
    }

    @Override
    public void removeOutputEventListener(OutputEventListener listener) {