Method onSubscribe

packages/query-core/src/mutationObserver.ts:96–102

()

  }

  protected onSubscribe(): void {
    if (this.listeners.size === 1 && this.#currentMutation) {
      this.#currentMutation.addObserver(this)

      this.#updateResult()
    }
  }

  protected onUnsubscribe(): void {
    if (!this.hasListeners()) {