onChanged property Null safety

ValueChanged<SfRangeValues>? onChanged

Called when the user is selecting a new values for the selector by dragging.

When the values of the range selector changes, the widget calls the onChanged callback with the new values.

SfRangeValues _initialValues = SfRangeValues(4.0, 8.0);

    min: 1.0,
    max: 10.0,
    initialValues: _initialValues,
    onChanged: (SfRangeValues values) {},
    child: Container(
        height: 200,
        color: Colors.green[100],


final ValueChanged<SfRangeValues>? onChanged;