@Override
      public Object call() {
        TXManagerImpl mgr = getGemfireCache().getTxManager();
        // Region<Integer, String> r = getGemfireCache().getRegion(D_REFERENCE);
        Region<CustId, Customer> pr = getGemfireCache().getRegion(CUSTOMER);
        CustId key = new CustId(0);
        Customer val = new Customer("name0", "address0");
        pr.put(key, val);
        mgr.begin();
        Entry entry = pr.getEntry(key);
        assertNotNull(entry);
        assertEquals(key, entry.getKey());
        assertEquals(val, entry.getValue());
        Entry entry2 = pr.getEntry(new CustId(10));
        assertNotNull(entry2);
        assertEquals(new CustId(10), entry2.getKey());
        assertNull(entry2.getValue());
        assertNull(pr.getEntry(new CustId(100)));
        mgr.commit();
        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