* @param fraction The parameter fraction for message. (NotNull)
     * @param integer The parameter integer for message. (NotNull)
     * @return this. (NotNull)
     */
    public FessMessages addConstraintsDigitsMessage(String property, String fraction, String integer) {
        assertPropertyNotNull(property);
        add(property, new UserMessage(CONSTRAINTS_Digits_MESSAGE, fraction, integer));
        return this;
    }