The message handler plug-in finalize function (ffh_mh_fini_function) for the message handler releases and cleans up any resources used by your message handler plug-in.
The ffh_mh_info argument of the finalization function points to the same object that was passed to the plug-in initialization function.
The plug-in should cast the ffh_mh_info->user_data field as a pointer to an instance of the message handling class, if one was created during the initialization, invoke its cleanup code, delete the object, and then set it to null.
The callback method publisherShutdown is required by the publisher API.