Search before asking

• I had searched in the issues and found no similar issues.

Question

These constants are used in multiple classes and are proposed to be placed in a Constant class.

Located in:eventmesh-examples/src/main/java/org/apache/eventmesh/tcp/demo/pub/eventmeshmessage/SyncRequest.java and eventmesh-examples/src/main/java/org/apache/eventmesh/tcp/demo/sub/eventmeshmessage/SyncResponse.java
You are advised to obtain it by reading the configuration file.
Such as:

Invalid code in AsyncSubscribe class can be removed.