StatefulBuilder constructor Null safety

const StatefulBuilder(
  1. {Key? key,
  2. required StatefulWidgetBuilder builder}
)

Creates a widget that both has state and delegates its build to a callback.

The builder argument must not be null.

Implementation

const StatefulBuilder({
  Key? key,
  required this.builder,
}) : assert(builder != null),
     super(key: key);