code: static Map<String, Object> patternPayload(final Object regex) {
  		if (regex == null) {
  			return null;
  		}
  		Map<String, Object> payload = new LinkedHashMap<>();
  		payload.put("value", regex);
  		payload.put("message", MSG_PREFIX + VALIDATORS.get(Pattern.class));
  		return payload;
  	}
docs: Creates a new map representing a {@link Pattern} validation constraint.
  @param regex a regular expression
  @return a map