Weird Dart Mixin

weird_dart_mixin.dart

void main() {
  Foo foo = Foo();
  print(foo.fromA);
  print(foo.fromB);

  print("=====================");

  Foo1 foo1 = Foo1();
  print(foo1.fromC);
  print(foo1.fromD);

  print("=====================");

  Foo2 foo2 = Foo2();
  print(foo2.fromA);
  print(foo2.fromB);
  print(foo2.fromC);
  print(foo2.fromD);
}

//-------------------------------------------

class Foo with A, B {
  Foo() {
    super.aValue = AValue('This is a value');
  }
}

class Foo1 with C, D {
  Foo1() {
    super.aValue = AValue('This is a value');
  }
}

class Foo2 with A, B, C, D {
  Foo2() {
    super.aValue = AValue('This is a value');
  }
}

//-------------------------------------------

mixin A {
  AValue aValue;
  String get fromA => '${aValue.value} from A';
}

mixin B {
  AValue aValue;

  String get fromB => '${aValue.value} from B';
}

mixin C {
  AValue _aValue;
  set aValue(AValue aValue) {
    _aValue = aValue;
  }

  String get fromC => '${_aValue.value} from C';
}

mixin D {
  AValue _aValue;
  set aValue(AValue aValue) {
    _aValue = aValue;
  }

  String get fromD => '${_aValue.value} from D';
}

//-------------------------------------------

class AValue {
  final String value;
  AValue(this.value);
}