null aware copywith

main.dart

class SomeThing {
  final String value1;
  final String? value2;

  SomeThing({
    this.value1 = 'first value',
    this.value2,
  });

  SomeThing copyWith({
    String? value1,
    String? value2,
  }) => SomeThing(
    value1: value1 ?? this.value1,
    value2: value2 ?? this.value2,
  );
}

void main() {
  SomeThing someThing = SomeThing(value2: 'second value');
  someThing = someThing.copyWith(value2: null);
  print(someThing.value2);
}