public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof TimePeriodValuesCollection)) {
            return false;   
        }
        TimePeriodValuesCollection that = (TimePeriodValuesCollection) obj;
        if (this.domainIsPointsInTime != that.domainIsPointsInTime) {
            return false;   
        }
        if (this.xPosition != that.xPosition) {
            return false;   
        }
        if (!ObjectUtilities.equal(this.data, that.data)) {
            return false;
        }
        return true;