function classFactory() {
  return class Foo {
    #foo = "foo";
    static #bar = "bar";

    instance() {
      return this.#foo;
    }

    static() {
      return Foo.#bar;
    }

    static instance(inst) {
      return inst.#foo;
    }

    static static() {
      return Foo.#bar;
    }
  };
}