@Override
      public void beforeUpdate(EntryEvent<Integer, String> event) throws CacheWriterException {
        throwException(event);
      }
start two servers and a client. make the server throw TransactionException. verify that the
exception does not cause the client to failover to the second server see bug 51666
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/ClientServerTransactionDUnitTest.java