protected ChartDataModelConstraints constraints1, constraints2;
/** Creates a new empty DefaultChartDataModel.
*/
public DefaultChartDataModel() {
TreeSet set1 = new TreeSet();
valuesbyaxis.put(new Integer(CoordSystem.FIRST_YAXIS), set1);
TreeSet set2 = new TreeSet();
valuesbyaxis.put(new Integer(CoordSystem.SECOND_YAXIS), set2);
constraints1 = new DefaultChartDataModelConstraints(this, CoordSystem.FIRST_YAXIS);
constraints2 = new DefaultChartDataModelConstraints(this, CoordSystem.SECOND_YAXIS);
}