@Override
            public Integer getUserCodeMinLengthAsInteger() {
                return 10;
            }

            @Override
            public Integer getUserCodeMaxLengthAsInteger() {
                return 20;
            }

            @Override
            public String getUserCodePattern() {
                return "[a-zA-Z0-9_]+";
            }
        };

    Integer getUserCodeMinLengthAsInteger();

    Integer getUserCodeMaxLengthAsInteger();

    default boolean isValidUserCode(final String userCode) {
        if (userCode == null) {
            return false;
        }

        final int length = userCode.length();
        if (getUserCodeMinLengthAsInteger().intValue() > length || getUserCodeMaxLengthAsInteger().intValue() < length) {
            return false;

     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not integer.
     */
    Integer getUserCodeMaxLengthAsInteger();

    /**
     * Get the value for the key 'user.code.pattern'. <br>
     * The value is, e.g. [a-zA-Z0-9_]+ <br>
     * comment: User code pattern for validation.