private void updatePing(PingSession pingSession) {
        // Avoid too frequent updates.
        final long currentTimeMillis = System.currentTimeMillis();
        if (PING_MIN_TIME_MILLIS < (currentTimeMillis - pingSession.getLastPingTimeMillis())) {
            return;
        }
        pingSession.setLastPingTimeMillis(currentTimeMillis);

        lifecycleListener.handshake(pingSession);
    }
@author Woonduk Kang(emeroad)
@author jaehong.kim
collector/src/main/java/com/navercorp/pinpoint/collector/grpc/lifecycle/DefaultPingEventHandler.java