public static String maskRegex(String input, String key, String name) {
        Map<String, Object> regexConfig = (Map<String, Object>) config.get(MASK_TYPE_REGEX);
        if (regexConfig != null) {
            Map<String, Object> keyConfig = (Map<String, Object>) regexConfig.get(key);
            if (keyConfig != null) {
                String regex = (String) keyConfig.get(name);
                if (regex != null && regex.length() > 0) {
                    return replaceWithMask(input, MASK_REPLACEMENT_CHAR.charAt(0), regex);
                }
            }
        }
        return input;
    }
@Test
    public void testMaskQueryParameter() {
        String test = "aaaa";
        String output = Mask.maskRegex(test, "queryParameter", "accountNo");
        System.out.println("output = " + output);
        Assert.assertEquals(output, "****");
    }