added cmdNumber 53874 for ack handling between backend and proxy

src/main/java/net/krakatoa/proxy/listener/SocketClientMessageListener.java

@@ -9,6 +9,7 @@ import de.dytanic.cloudnet.ext.bridge.player.ICloudPlayer;
 import de.dytanic.cloudnet.ext.bridge.player.IPlayerManager;
 import de.dytanic.cloudnet.ext.bridge.player.ServicePlayer;
 import earth.krakatao.events.KraSocketClientEventInterface;
+import earth.krakatao.protocol.KraSocketClientProtocolDest;
 import earth.krakatao.protocol.KraSocketClientProtocolMessage;
 import earth.krakatao.protocol.KraSocketClientProtocolStatus;
 import java.util.Collection;
@@ -156,6 +157,21 @@ public class SocketClientMessageListener implements KraSocketClientEventInterfac
         }
         break;
       }
+      case 53874: { // test message - ack
+        KraSocketClientProtocolMessage kraSocketClientProtocolMessage = new KraSocketClientProtocolMessage(
+            KraSocketClientProtocolStatus.GET.getStatus(),
+            kraProtocolMessage.getCmdID(), KraSocketClientProtocolDest.BACKEND.getStatus(),
+            kraProtocolMessage.getUuid(),
+            (short) 53874, "");
+
+        ProxySystem.getInstance().getKraSocketClient().getSocketClient()
+            .SendMessage(kraSocketClientProtocolMessage);
+
+        System.out.println(
+            "cmdNumber 53874 answered back to uuid:" + kraProtocolMessage.getUuid()
+                + " cmdIDByBackend:"
+                + kraProtocolMessage.getCmdID());
+      }
       default:
 
         break;