* @param xKey The {@link IKey} that identifies the X data source
* @param yKey The {@link IKey} that identifies the Y data source
* @return Whether the widget was successfully connected
*/
public <TI extends IChartViewer, U> boolean connectWidgetDual(TI widget, IKey xKey, IKey yKey) {
CompositeKey compKey = new CompositeKey();
compKey.addKey(CompositeKey.X_INDEX, xKey);
compKey.addKey(CompositeKey.Y_INDEX, yKey);
return connectWidget(widget, compKey);
}