diff --git a/lib/socket/protobuf_client.dart b/lib/socket/protobuf_client.dart
index b845243..4c3b52a 100644
--- a/lib/socket/protobuf_client.dart
+++ b/lib/socket/protobuf_client.dart
@@ -42,7 +42,6 @@ abstract class ProtobufClient extends Communicator
       _heartbeatChecker?.responsed();
       _heartbeatChecker = ResponseChecker.second(this, _heartbeatIntervalTime, (client) {
         if(_isAlive) {
-          print('=== sendHartBeat');
           send(HeartBeat());
           _heartbeatChecker = ResponseChecker.second(this, _heartbeatWaitTime, (client) {
             if(_isAlive) {
@@ -172,6 +171,7 @@ class ResponseChecker<T> {
   late int _time;
   late Timer? _timer = null;
   late void Function(T) _notResponseListener;
+  T get responser => _responser;
   ResponseChecker(this._responser, this._time, this._notResponseListener) {
     startTimer();
   }
diff --git a/lib/utils/system_util.dart b/lib/utils/system_util.dart
index 93175f9..97b8f11 100644
--- a/lib/utils/system_util.dart
+++ b/lib/utils/system_util.dart
@@ -16,6 +16,9 @@ void initialize() {
   getDataPath = getDataPath_;
 }
 
+const int intMax =  0x7FFFFFFFFFFFFFFF;
+const int intMin = -0x8000000000000000;
+
 Map<String, List<String>?> envArguments(List<String> arguments) {
   var dic = <String, List<String>?>{};
   var list = <String>[];