createRenderer method
Create the circular series renderer.
Implementation
DoughnutSeriesRenderer? createRenderer(CircularSeries<T, D> series) {
DoughnutSeriesRenderer? seriesRenderer;
if (onCreateRenderer != null) {
seriesRenderer = onCreateRenderer!(series) as DoughnutSeriesRenderer;
// ignore: unnecessary_null_comparison
assert(seriesRenderer != null,
'This onCreateRenderer callback function should return value as extends from ChartSeriesRenderer class and should not be return value as null');
return seriesRenderer;
}
return DoughnutSeriesRenderer();
}