class NameOrCrn {

    public static NameOrCrn ofCrn(String crn) {
        if (StringUtils.isEmpty(crn)) {
            throw new IllegalArgumentException(CRN_MUST_BE_PROVIDED_EXCEPTION_MESSAGE);
        }
        return new NameOrCrn(null, crn);
    }

    private  NameOrCrn(String name, String crn);

}