private void updateStage(Operation op,SubStage stage){
  TransactionServiceState existing=getState(op);
  existing.taskSubStage=stage;
  setState(op,existing);
}

private void updateStage ( Operation op , SubStage stage ) { TransactionServiceState existing = getState ( op ) ; existing . taskSubStage = stage ; setState ( op , existing ) ; }
update stage to new stage
