toJson method
Convert configuration to JSON
Implementation
@override
Map<String, dynamic> toJson() => {
'type': 'nestedPie',
..._pieConfigJson(this),
'rings': rings.map((ring) => ring.toJson()).toList(),
'series': [
for (final ring in rings) _sliceSeries(ring.slices, name: ring.name),
],
'ringGap': ringGap,
'padAngle': padAngle,
};