@Override
  public void verifyVersionTags(VM client, VM server1, VM server2, VM server3) {
    Map<Object, VersionTag> clientTags = getVersionTagsForRegion(client, D_REFERENCE);
    Map<Object, VersionTag> serverTags = getVersionTagsForRegion(server1, D_REFERENCE);

    InternalDistributedMember serverId = getMemberId(server1);
    for (Object key : clientTags.keySet()) {
      VersionTag serverTag = serverTags.get(key);
      serverTag.setMemberID(serverId);
      LogWriterUtils.getLogWriter().fine("SWAP:key:" + key + " clientVersion:" + clientTags.get(key)
          + " serverVersion:" + serverTag);
      assertEquals(clientTags.get(key), serverTags.get(key));
      serverTags.remove(key);
    }
    assertTrue(serverTags.isEmpty());
  }
test client initiated transactions with concurrency checks enabled.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/ClientServerTransactionCCEDUnitTest.java