public static Number findMaximumStackedRangeValue(CategoryDataset dataset) {

        Number result = null;

        if (dataset != null) {
            double maximum = 0.0;
            int categoryCount = dataset.getColumnCount();
            for (int item = 0; item < categoryCount; item++) {
                double total = 0.0;
                int seriesCount = dataset.getRowCount();
                for (int series = 0; series < seriesCount; series++) {
                    Number number = dataset.getValue(series, item);
                    if (number != null) {
                        double value = number.doubleValue();
                        if (value > 0.0) {
                            total = total + value;
                        }
                    }
                }
                maximum = Math.max(maximum, total);
            }
            result = new Double(maximum);
        }

        return result;