getArcLists method
Returns the List of AnimatedArcList associated with the renderer. The Pie Chart has one AnimatedArcList and the Sunburst chart usually has multiple elements.
Implementation
@override
List<AnimatedArcList<D>> getArcLists({String? seriesId}) {
  if (seriesId == null) {
    return _seriesArcMap.values.toList();
  }
  final arcList = _seriesArcMap[seriesId];
  if (arcList == null) return <AnimatedArcList<D>>[];
  return [arcList];
}