class Lazy {
  #factory;
  #initialized = false;
  #value;

  constructor(factory) {
    this.#factory = factory;
  }

  get initialized() {
    return this.#initialized;
  }

  get value() {
    if (!this.#initialized) {
      this.#initialized = true;
      this.#value = this.#factory();
      this.#factory = null;
    }
    return this.#value;
  }
}