public String extractLastName(String fullName)throws Exception {
        if (fullName == null || fullName.length() <= 1) {
            throw new IllegalArgumentException(ERR_NAME);
        }
        String[] nameParts = fullName.trim().split(" ");
        if (nameParts.length > 2) {
            nameParts[1] = nameParts[2];
        } else if (nameParts.length > 1) {
            nameParts[0] = nameParts[1];
        }
        return nameParts[LAST_NAME_IDX];
    }