* @return The minimum value (possibly {@code null}).
*/
public static Number findMinimumRangeValue(CategoryDataset dataset) {
ParamChecks.nullNotPermitted(dataset, "dataset");
if (dataset instanceof RangeInfo) {
RangeInfo info = (RangeInfo) dataset;
return new Double(info.getRangeLowerBound(true));
}
// hasn't implemented RangeInfo, so we'll have to iterate...
else {
double minimum = Double.POSITIVE_INFINITY;