legendItemBuilder property Null safety

LegendItemBuilder? legendItemBuilder

Widget builder for legend items.

Customize the appearance of legend items in template by using legendItemBuilder property of legend.

Defaults to null.

Widget build(BuildContext context) {
  return SfCartesianChart(
    legend: Legend(
      isVisible: true,
      legendItemBuilder: (String name, dynamic series,dynamic point, int index) {
        return Container(
          height: 30,
          width: 80,
          child: Row(
            children: <Widget>[
              Container(child: Image.asset('images/bike.png')),
              Container(child: Text(index.toString())),


final LegendItemBuilder? legendItemBuilder;