class B extends Object with M1, M2 {
  B(value);
}

class C extends Object with M1, M2 {
  C(value);
}

class D<S> extends Object with G1<S> {}

main() {}

mixin G1<T> {
  m() => print(T);
}

mixin M1 {
  m() => print("M1");
}

mixin M2 {
  m() => print("M2");
}