def listener = new TestListener()

        when:
        renderer.enableUserStandardOutputListeners()
        renderer.addStandardOutputListener(listener)
        renderer.removeStandardOutputListener(listener)
        renderer.onOutput(event('info', LogLevel.INFO))
        renderer.onOutput(event('error', LogLevel.ERROR))

        then:
        listener.value == ''
    }

    public void addStandardErrorListener(OutputStream outputStream) {
        addStandardErrorListener(new StreamBackedStandardOutputListener(outputStream));
    }

    @Override
    public void removeStandardOutputListener(StandardOutputListener listener) {
        synchronized (lock) {
            assertUserListenersEnabled();
            userStdoutListeners.remove(listener);
        }
    }

    @Override