createRenderer method Null safety

BoxAndWhiskerSeriesRenderer createRenderer(
  1. ChartSeries<T, D> series
)

Create the Box and Whisker series renderer.

Implementation

BoxAndWhiskerSeriesRenderer createRenderer(ChartSeries<T, D> series) {
  BoxAndWhiskerSeriesRenderer seriesRenderer;
  if (onCreateRenderer != null) {
    seriesRenderer = onCreateRenderer!(series) as BoxAndWhiskerSeriesRenderer;
    // 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 BoxAndWhiskerSeriesRenderer();
}