public OccupationPeriod(Date startDate, Date endDate) { this(); this.setStart(startDate); this.setEnd(endDate);
public OccupationPeriod() { super(); setRootDomainObject(RootDomainObject.getInstance());
    public OccupationPeriod(Date startDate, Date endDate) {    	this();        this.setStart(startDate);        this.setEnd(endDate);    }