CHALLENGE

class Counter {
#count = 0;
static #instances = 0;
constructor() { Counter.#instances++; }
#increment() { this.#count++; }
incrementAndGet() {
this.#increment();
return this.#count;
}
static get total() { return Counter.#instances; }
}

class SpecialCounter extends Counter {
incrementAndGet() {
return super.incrementAndGet() * 2;
}
}

const c1 = new Counter();
const c2 = new SpecialCounter();
console.log(`${c1.incrementAndGet()} ${c2.incrementAndGet()} ${Counter.total}`);