final Table<R, C, V> delegate = HashBasedTable.create();
    public final Object mutex = new Object[0]; // something Serializable

    @Override
    public String toString() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.toString();
    }

    @Override
    public boolean equals(@Nullable Object o) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.equals(o);
    }

        // Test: update settings api
        final Map<String, Object> updateMap = getUpdateMap();
        final Map<String, Object> searchBody = createSearchBody(SEARCH_ALL_NUM);
        List<Map<String, Object>> settings = getItemList(searchBody);

        for (Map<String, Object> setting : settings) {
            final Map<String, Object> requestBody = new HashMap<>(updateMap);
            final String idKey = getIdKey();

                    "required": ["ok"],
                    "type": "object",
                    "properties": {"ok": {"title": "Ok", "type": "boolean"}},
                },
                "ValidationError": {
                    "title": "ValidationError",
                    "required": ["loc", "msg", "type"],
                    "type": "object",
                    "properties": {
                        "loc": {

    }

    @Override
    protected String getItemEndpointSuffix() {
        return ITEM_ENDPOINT_SUFFIX;
    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);

    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);
        requestBody.put("value", new Integer(id).toString());
        return requestBody;
    }

    @Override
    protected Map<String, Object> getUpdateMap() {

    }

    @Override
    protected String getItemEndpointSuffix() {
        return ITEM_ENDPOINT_SUFFIX;
    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);
        requestBody.put("replacement", "replacement" + id);

    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();
        final String keyProp = NAME_PREFIX + id;
        requestBody.put(KEY_PROPERTY, keyProp);
        requestBody.put("output", "output");
        return requestBody;
    }

    @Override
    protected Map<String, Object> getUpdateMap() {

        setCreatedBy_GreaterThan(createdBy, null);
    }

    public void setCreatedBy_GreaterThan(String createdBy, ConditionOptionCall<RangeQueryBuilder> opLambda) {
        final Object _value = createdBy;
        RangeQueryBuilder builder = regRangeQ("createdBy", ConditionKey.CK_GREATER_THAN, _value);
        if (opLambda != null) {
            opLambda.callback(builder);
        }
    }

  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> newHashMapWithExpectedSize(int expectedSize) {
    return CompactHashMap.createWithExpectedSize(expectedSize);
  }

  /**
   * Returns the platform preferred implementation of an insertion ordered map based on a hash
   * table.
   */
  static <K extends @Nullable Object, V extends @Nullable Object>

  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> newHashMapWithExpectedSize(int expectedSize) {
    return Maps.newHashMapWithExpectedSize(expectedSize);
  }

  /**
   * Returns the platform preferred implementation of an insertion ordered map based on a hash
   * table.
   */
  static <K extends @Nullable Object, V extends @Nullable Object>