*/
    protected JsonUtil() {
    }

    /**
     * Escapes a value as Json string.
     *
     * @param value input
     * @return escaped string.
     */
    public static String escape(final String value) {
        if (value == null) {
            return null;
        }

        char c;
        final int len = value.length();
        final StringBuilder buf = new StringBuilder(len * 2);

    while (set.size() < size) {
      set.add(newElement());
    }
    return set;
  }

  private Element newElement() {
    int value = random.nextInt();
    return isUserTypeFast ? new Element(value) : new SlowElement(value);
  }

  static class Element implements Comparable<Element> {
    final int hash;

    Element(int hash) {
      this.hash = hash;
    }

        if (crudMode != expectedMode) {
            throwValidationError(messages -> {
                messages.addErrorsCrudInvalidMode(GLOBAL, String.valueOf(expectedMode), String.valueOf(crudMode));
            }, this::asListHtml);
        }
    }

    // ===================================================================================

    @Override
    public Object execute(String expression, Object value) {
        expression = ValueSourceUtils.trimPrefix(expression, expressionPrefixes, true);

        if (projectDir != null && value != null && unprefixedPathKeys.contains(expression)) {
            return pathTranslator.alignToBaseDirectory(String.valueOf(value), projectDir);
        }

        return value;
    }

        String result = StringUtil.join("-", "", null, "value", "", null);
        // First: "" (sb becomes "")
        // Second: sb.length() is 0, no delimiter, append null (sb becomes "null")
        // Third: sb.length() > 0, add "-" + "value" (sb becomes "null-value")
        // Fourth: sb.length() > 0, add "-" + "" (sb becomes "null-value-")
        // Fifth: sb.length() > 0, add "-" + null (sb becomes "null-value--null")

        if (crudMode != expectedMode) {
            throwValidationError(messages -> {
                messages.addErrorsCrudInvalidMode(GLOBAL, String.valueOf(expectedMode), String.valueOf(crudMode));
            }, this::asListHtml);
        }
    }

    // ===================================================================================

            throwValidationError(messages -> {
                messages.addErrorsCrudInvalidMode(GLOBAL, String.valueOf(expectedMode), String.valueOf(crudMode));
            }, () -> asListHtml(dictId));
        }
    }

    private static void validateStopwordsString(final String values, final String propertyName, final VaErrorHook hook) {
        // TODO validation
    }

        try {
            final boolean result = validator.isValid("test", null);
            assertNotNull("isValid should return a boolean result", Boolean.valueOf(result));
        } catch (final NullPointerException e) {
            // This is expected if the implementation requires a non-null context

        //        searchName = Srl.substringFirstRear(classificationName, ".");
        //    } else {
        //        return null;
        //    }
        //}
        //try {
        //    return CDef.DefMeta.valueOf(searchName);
        //} catch (IllegalArgumentException ignored) { // not found
        //    return null; // handled later
        //}
    }

    @Override

        if (crudMode != expectedMode) {
            throwValidationError(messages -> {
                messages.addErrorsCrudInvalidMode(GLOBAL, String.valueOf(expectedMode), String.valueOf(crudMode));
            }, this::asListHtml);
        }
    }

    // ===================================================================================