SignalR : Java Client : stop in on doesn't work

Hello,
my existing java client code migrated to Core cannot stop...
seems that the state never change even if i call stop() several times.. is there a workaround ?

```
while (Connection.getConnectionState() != HubConnectionState.DISCONNECTED) {
try {
Connection.stop();
Thread.sleep(100);
}
catch (InterruptedException e) {
e.printStackTrace();
}
}
System.exit(0);
```