class Class1 {
  Class1._();
  factory Class1() = Class1._;
}

class Class2 {
  Class2.__();
  factory Class2._() => Class2.__();
  factory Class2.named() = Class2._;
}

class Class3 {
  Class3._(this.field);
  factory Class3(int field) = Class3._;
  final int field;
}

class Class4 {
  Class4._([this.field]);
  factory Class4([int? field]) = Class4._;
  final int? field;
}

class Class5 {
  Class5._(this.field1, [this.field2]);
  factory Class5(int field1, [int? field2]) = Class5._;
  final int? field2;
  final int field1;
}

class Class6 {
  Class6._(this.field1, {this.field2, required this.field3});
  factory Class6(int field1, {int? field2, required int field3}) = Class6._;
  final int? field2;
  final int field1;
  final int field3;
}

class Class7a implements Class7b {
  Class7a();
}

class Class7b {
  factory Class7b() = Class7a;
}

class Class8a<T> implements Class8b<T> {
  Class8a();
}

class Class8b<T> {
  factory Class8b() = Class8a<T>;
}

expect(expected, actual) {}
final bool inSoundMode = <int?>[] is! List<int>;
main() {}
testArgs() {}
testNoArgs() {}
throws(Function() f, {bool inSoundModeOnly: false}) {}