@OnError public void onError(Session session,Throwable t){
  callInternal("onError",session,t.getMessage());
  logger.error(t.getMessage(),t);
}

@ OnError public void onError ( Session session , Throwable t ) { callInternal ( "onError" , session , t . getMessage ( ) ) ; logger . error ( t . getMessage ( ) , t ) ; }
on error raised handler
