@Override
      public Object call() {
        Region<CustId, Customer> pr = getGemfireCache().getRegion(CUSTOMER);
        /* CacheTransactionManager mgr = */ getCache().getCacheTransactionManager();
        pr.put(new CustId(0), new Customer("name0", "address0"));
        pr.put(new CustId(1), new Customer("name1", "address1"));
        return null;
      }
test has a client, two accessors and a datastore pool connects to two accessors. we then close
the server in first accessor and verify failover
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/ClientServerTransactionDUnitTest.java