### Question:
TransactionalMessageServiceImpl implements TransactionalMessageService { @Override public boolean open() { return true; } TransactionalMessageServiceImpl(TransactionalMessageBridge transactionBridge); @Override PutMessageResult prepareMessage(MessageExtBrokerInner messageInner); @Override void check(long transactionTimeout, int transactionCheckMax,
        AbstractTransactionalMessageCheckListener listener); @Override boolean deletePrepareMessage(MessageExt msgExt); @Override OperationResult commitMessage(EndTransactionRequestHeader requestHeader); @Override OperationResult rollbackMessage(EndTransactionRequestHeader requestHeader); @Override boolean open(); @Override void close();  }### Answer:
@Test public void testOpen() { boolean isOpen = queueTransactionMsgService.open(); assertThat(isOpen).isTrue(); }