throw new IllegalArgumentException("Null 'dataset' argument.");
}
Number result = null;
// if the dataset implements DomainInfo, life is easy
if (dataset instanceof DomainInfo) {
final DomainInfo info = (DomainInfo) dataset;
return new Double(info.getDomainLowerBound(true));
} else {
double minimum = Double.POSITIVE_INFINITY;
final int seriesCount = dataset.getSeriesCount();
for (int series = 0; series < seriesCount; series++) {
final int itemCount = dataset.getItemCount(series);