@Test
  public void testReadBadZNRecordCase6() throws Exception {
    ZNRecord zNRecord = new ZNRecord(String.valueOf(System.currentTimeMillis()));
    Map<String, String> accountMap = new HashMap<>();
    accountMap.put(String.valueOf(refAccount.getId()), objectMapper.writeValueAsString(
        new AccountBuilder(refAccount).snapshotVersion(refAccount.getSnapshotVersion() + 1).build()));
    accountMap.put(String.valueOf(refAccount.getId() + 1), BAD_ACCOUNT_METADATA_STRING);
    if (useNewZNodePath) {
      String blobID = RouterStore.writeAccountMapToRouter(accountMap, mockRouter);
      List<String> list = Collections.singletonList(new RouterStore.BlobIDAndVersion(blobID, 1).toJson());
      zNRecord.setListField(RouterStore.ACCOUNT_METADATA_BLOB_IDS_LIST_KEY, list);
    } else {
      zNRecord.setMapField(LegacyMetadataStore.ACCOUNT_METADATA_MAP_KEY, accountMap);
    }
    updateAndWriteZNRecord(zNRecord, false);
  }
Tests reading {@link ZNRecord} from {@link HelixPropertyStore}, where the {@link ZNRecord} has an invalid account
record and a valid account record. This is a NOT good {@link ZNRecord} format and it should fail fetch or update
operations, with none of the record should be read.
@throws Exception Any unexpected exception.
ambry-account/src/test/java/com/github/ambry/account/HelixAccountServiceTest.java