@Override
    public void start() {
        this.checkerScheduler = Threads.newSingleThreadScheduledExecutor(ThreadUtils.createThreadFactory("back-pressure-checker-%d", false), LOGGER, true, false);
        S3StreamKafkaMetricsManager.setBackPressureStateSupplier(this::stateMetrics);
    }
The current state metrics of the system.
Only used for monitoring.

@see S3StreamKafkaMetricsManager#setBackPressureStateSupplier
core/src/main/java/kafka/automq/backpressure/DefaultBackPressureManager.java