private void initManager(boolean enabled, long cooldownMs) {
        config = new BackPressureConfig(enabled, cooldownMs);
        manager = new DefaultBackPressureManager(config, regulator);
        manager.checkerScheduler = scheduler;
    }
Should be called at the beginning of each test to initialize the manager.
core/src/test/java/kafka/automq/backpressure/DefaultBackPressureManagerTest.java