attachTo method
Injects the behavior into a chart.
Implementation
@override
void attachTo(BaseChart<D> chart) {
if (!(chart is SunburstChart)) {
throw ArgumentError(
'SunburstRingExpander can only be attached to a Sunburst chart');
}
_chart = chart as SunburstChart<D>;
chart
.getSelectionModel(selectionModelType)
.addSelectionUpdatedListener(_selectionChanged);
}