if (dataset != null) {
            Range r = DatasetUtilities.findDomainBounds(dataset, false);
            if (r == null) {
                return null;
            }
            else {
                return new Range(r.getLowerBound() + this.xOffset,
                        r.getUpperBound() + this.blockWidth + this.xOffset);
            }
        }
        else {
            return null;