child property Null safety

Widget child

Specifies a widget that can hold single child.

This snippet shows how to set value to the child property in SfRangeSliderTheme and SfRangeSelectorTheme.

SfRangeValues _values = SfRangeValues(4.0, 7.0);

  body: Center(
      child: SfRangeSliderTheme(
          data: SfRangeSliderThemeData(
              trackHeight: 3,
          child:  SfRangeSlider(
              min: 2.0,
              max: 10.0,
              values: _values,
              interval: 2,
              showTicks: true,
              showLabels: true,
              onChanged: (SfRangeValues newValues){
                  setState(() {
                      _values = newValues;


final Widget child;