if (point.hasAttributes(fixedPeriodAttribute, DomainConstants.WORKED_ATTRIBUTES)) {
if (point.hasAttributes(fixedPeriodAttribute, DomainConstants.WORKED_ATTRIBUTES) || point.hasAttributes(fixedPeriodAttribute, AttributeType.BALANCE)) {
    public Duration calculateFixedPeriod(AttributeType fixedPeriodAttribute) {        List<TimePoint> pointList = new ArrayList<TimePoint>();        for (TimePoint point: getTimePoints()) {            if (point.hasAttributes(fixedPeriodAttribute, DomainConstants.WORKED_ATTRIBUTES)) {                pointList.add(point);            }        }        return this.calculateDurationPointList(pointList);    }    