getset.js

  set(key, value) {
    let result = super.set(key, value);

    // Update the frequency of the key
    this.#updateFrequency(key);

    return result;
  }

  get(key) {
    let exists = super.get(key);

    // Don't update non existing gets
    if (exists)
      this.#updateFrequency(key);

    return exists;
  }
}