gradient property Null safety

Gradient? gradient

A gradient to use when filling the axis line.

gradient of AxisLineStyle only support SweepGradient and specified SweepGradient.stops are applied within the axis range value.

Defaults to null.

Widget build(BuildContext context) {
   return Container(
       child: SfRadialGauge(
          AxisLineStyle(dashArray: <double>[5, 5],
          gradient: SweepGradient(
                  colors: const <Color>[Colors.deepPurple,,
                    Color(0xFFFFDD00), Color(0xFFFFDD00),
                    Color(0xFF30B32D), ],
                  stops: const <double>[0,0.03, 0.5833333, 0.73, 1],


final Gradient? gradient;