@Override
      public Object call() {
        for (CacheServer s : getCache().getCacheServers()) {
          getCache().getLogger().info("SWAP:Stopping " + s);
          s.stop();
        }
        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