void stop() {
        if (stop.compareAndSet(false, true)) {
            logger.info("DeadlockMonitorTask stop started");
        } else {
            logger.info("DeadlockMonitorTask already stopped");
        }
    }
refer to java.lang.management.ThreadInfo.toString {@link ThreadInfo}
To find loadClass cause. MAX_FRAME is too short , the length.
agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/monitor/DeadlockMonitorTask.java