class Base {
  #value = 0;
  get value() { return this.#value; }
  set value(v) { this.#value = v * 2; }
}
class Derived extends Base {
  get value() { return super.value + 1; }
  set value(v) { super.value = v + 10; }
}
const d = new Derived();
d.value = 5;
console.log(d.value, d.value = 100, d.value);