if (author == null) { throw new DomainException("error.ResultPatent.participations.cannot.be.null"); }
    private void checkParameters(String title, Partial registrationDate, Partial approvalDate, Person author) {        if (title == null || title.equals("")) {            throw new DomainException("error.ResultPatent.title.cannot.be.null");        }        if (registrationDate == null) {            throw new DomainException("error.ResultPatent.registrationDate.cannot.be.null");        }        if (approvalDate == null) {            throw new DomainException("error.ResultPatent.approvalDate.cannot.be.null");        }        if(!isApprovalDateAfterRegistrationDate(approvalDate, registrationDate)){            throw new DomainException("error.ResultPatent.approvalDate.before.registrationDate");        }        if (author == null) {            throw new DomainException("error.ResultPatent.participations.cannot.be.null");        }    }